Moors murderer Ian Brady is thought to have revealed where one of his victims, 12-year-old Keith Bennett, is buried.

Police are investigating whether Brady has written a letter to be opened on his death revealing the location of Keith’s body, but senior detective Martin Bottomley said: “We do not know if this is true or simply a ruse.”

Greater Manchester Police launched their investigation after Brady's mental health advocate told a Channel 4 documentary that he gave her a sealed envelope to pass to Winnie Johnson, the mother of Keith Bennett, in the event of his death.

Jackie Powell, Brady's legal advocate, was arrested in South Wales on suspicion of preventing the burial of a body without lawful exercise and has since been released on bail pending further inquiries.

keith bennett

The body of 12-year-old Keith has never been found despite repeated searches on Saddleworth Moor in Manchester

Brady may have revealed the location of Keith's grave in documents passed to 49-year-old Powell with strict orders they are only to be opened after his death.

However detectives searching Ms Powell's home have so far found no evidence to suggest Brady has disclosed the location of Keith's body.

ian brady

Ian Brady smoking a cigarette while in police custody during the 1966 trial

Bottomley said in a statement: "The Moors murders cast a long and dark shadow over the history of our region but in 2009 we reluctantly concluded there was no longer any specific information to identify new search areas and the investigation to find Keith entered a dormant stage.

"However, we have always stressed this is a case we will never close. We have been, and always will be, open to pursuing any new lines of inquiry that arise from significant scientific advances or credible and actionable information.

"I want to be explicitly clear about this: Ian Brady has not revealed to police the location of Keith's body.

"What we are looking at is the possibility, and at this stage it is only a possibility, that he has written a letter to Keith's mum Winnie Johnson which was not to be opened until after his death.

"We do not know if this is true or simply a ruse but we clearly have a duty to investigate such information on behalf of Keith's family.

Brady has always refused to disclose the location of Keith's body.

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  • Brady discloses location of victim's body

    Undated file photo of Ian Brady. Detectives believe the Moors murderer has recently given details of the location of the body of one of his victims, 12-year-old Keith Bennett, to one of his long-term visitors, Greater Manchester Police said in a statement.

  • Brady discloses location of victim's body

    Undated handout file photo of Keith Bennett. Detectives believe the Moors murderer Ian Brady has recently given details of the location of the body of one of his victims, 12-year-old Bennett, to one of his long-term visitors, Greater Manchester Police said in a statement.

  • Brady discloses location of victim's body

    File photo dated 26/3/2010 of Winnie Johnson, mother of Keith Bennett. Detectives believe the Moors murderer has recently given details of the location of the body of one of his victims, 12-year-old Bennett, to one of his long-term visitors, Greater Manchester Police said in a statement.

  • Winnie Johnson, mother of Keith Bennett, on Saddleworth Moor, Saddleworth, as a privately funded search has begun for the body of the 12-year-old boy killed by Moors Murderers Ian Brady and Myra Hindley. (Photo credit: PA)

  • THE MOORS MURDERS: Heavily swathed in plastic sheeting, human remains are carried from the screened grave on Saddleworth Moor, near Ashton-under-Lyne. Detective Chief Superintendent Sam Cross, head of the West Riding CID, said they were now making inquiries to establish the identity of the body. Myra Hindley and Ian Brady.

  • Ian Brady in the back of a police car prior to his court appearance for the Moors Murders for which he was later convicted. Archive-PA122200-52

  • PA NEWS PHOTO 8/12/65 THE DEFENCE COUNSEL IN HYDE, CHESHIRE FOR THE MOORS MURDER CHARGES HEARING AT THE MAGISTRATES COURT: DAVID LLOYD JONES (NEAR CAMERA) WHO IS APPEARING FOR IAN BRADY (27 YEAR OLD) STOCK CLERK ACCUSED OF THREE MURDERS AND MR. PHILIP COLLINS APPEARING FOR ESTHER MYRA HINDLEY, THE 23 YEAR OLD SHORT-HAND TYPIST ACCUSED OF TWO MURDERS

  • A police mounted search Saddleworth Moor near Woodhead for the bodies of the victims of the Moors Murderers. The Moors murders were committed by Ian Brady and Myra Hindley around the Manchester area of England between 1963 and 1965. The Moors murders are so named because four of the victims were buried to the north of the A635, Greenfield Road, over Saddleworth Moor between Oldham, then in Lancashire, and the Wessenden Road junction to Meltham, then in the West Riding of Yorkshire. Their five victims were children aged between 10 and 17 years.

  • A witness in the Moors Murder case, who gave evidence in the resumed hearing.

  • A Police party digging on the Saddleworth Moors in Yorkshire looking for moorland graves. Pictured to the right is six canes to mark the spot where the body of ten-year old Lesley Ann Downey was found in a shallow grave, victim of the Moors Murderers Ian Brady and Myra Hindley.

  • Detective Chief Inspector Joseph Mounsey of the Lancashire Police where he gave evidence at the charges hearing.

  • A composite picture of 12 year old Keith Bennett (L) and 16 year old Pauline Reade, who went missing around 30 years ago at the time of the Moors Murders. Myra Hindley and her lover Ian Brady were jailed in 1966 for the Moors murders. * Pauline Read's body was found on Saddleworth Moor, it was confirmed 03/07/1987.

  • Police use specially trained sniffer dogs, on Saddleworth Moor, near Oldham. They are searching for the bodies of Pauline Reade, 16, and Keith Bennett, 12, who disappeared at the time of the Moors murders more than 20 years ago.

  • Police dig at one of the spots indicated by specially trained sniffer dogs, on Saddleworth Moor, near Oldham. They are searching for the bodies of Pauline Reade, 16, and Keith Bennett, 12, who disappeared at the time of the Moors murders more than 20 years ago.

  • Moors Murderers Myra Hindley (L) and Ian Brady. The Director of Public Prosecutions, Allan Green QC, has decided it would be in the public interest to institute criminal proceedings against the killers, in relation to the deaths of Pauline Reade or Kieth Bennett. * 28/12/1999 : Hindley was tonight in hospital after being taken ill in prison. Hindley, aged 57, was this afternoon taken by ambulance from Highpoint Prison, Suffolk, to the West Suffolk Hospital in nearby Bury St Edmunds. *14/1/88 of Moors Murderers Ian Brady. A book written by Brady about serial killing could be banned in Britain, it was reported. The Gates of Janus, which is said to profile the minds of serial killers such as Peter Sutcliffe, has been sold to American publisher, Feral House, and will be in US bookshops by the end of the year. Under a deal with a British distributor, copies of the 300-page book were due to go on sale in the UK November. But BBC News Online said today that Ashworth Hospital, where Brady is being held, has won a temporary injunction stopping publication in Britain while the book's contents are checked.

  • Mrs Winifred Johnson, the mother of Moors murder victim Keith Bennett, on Saddleworth Moor with Det Chief Supt Peter Topping, the man leading the hunt for her son's body. Mrs Johnson was in London trying to persuade the Home Secretary to allow Myra Hindley to be hypnotised in the hope she can identify where the 12-year-old is buried.

  • Mrs Winnie Johnson with her 23 year old son Joey, digging on Saddleworth Moor near Manchester in a bid to find the remains of her 12 year old son Keith Bennett, victim of the Moors Murderers Myra Hindley and Ian Brady.

  • Ann and Alan West, the parents of Moors murder victim Leslie Ann Downey, at the Victims of Crime Trust launch. Lesley, 10, was snatched from a fair on Boxing Day 1964. Her body was found on Saddleworth Moor late 1965. * 9/2/99: Ann West died at home, aged 69.

  • Winnie Johnson, 65, from Manchester whose son Keith Bennett was one of the Moors murder victims, joins walkers in Dunblane starting a march to London. The charity Mothers Against Murder and Aggression hopes to raise money for a retreat and resource centre. *13/10/00 Mrs Johnson said that it would be wrong to release Hindley from jail under the new Human Rights Act, as suggested by the Lord Chief Justice Lord Woolf.

  • Winnie Johnson, mother of moors murder victim Keith Bennett, outside the High Court today (Thursday) after hearing the news that Myra Hindley's bid to overturn the decision that she must die in prison had failed. See PA story COURTS Hindley. Photo by Ben Curtis/PA

  • Winnie Johnson wipes away a tear at a rally organised by the 'Mothers Against Murder and Aggression' held in Kensington Gardens, London. Winnie's son Keith Bennett was murdered by the "Moors Murderers" over 30 years ago and his body has never been found.

  • Meg Colpitts (L), from Newcastle and founder of Justice for Children, comforts Winnie Johnson who broke down in tears at a rally organised by Dee Warner (R) from the 'Mothers Against Murder and Aggression' held in Kensington Gardens, London. * Winnie's son Keith Bennett was murdered by the "Moors Murderers" over 30 years ago and his body has never been recovered.

  • Winnie Johnson, whose son Keith Bennett was killed by the "Moors Murderers" is hugged by American Marc Klaas, daughter Polly was also murdered. The two met during a rally organised by the 'Mothers Against Murder and Aggression' held in Kensington Gardens. * in London. Keith Bennett's body has never been recovered.

  • Winnie Johnson (left) the mother of Keith Bennett who's body is still missing, with Psychic Teresa Walsh (holding Keith's spectacles) on the Yorkshire Moors. * A BBC documentary Body Hunt: The Search for Keith Bennett is to be shown revealing that Mira Hindley has helped draw three maps which show the route she and Ian Brady took in 1964 onto Saddleworth Moor with 12-year-old Keith Bennett the night he was killed. Hindley and Brady were given life in 1966 for the murders of Lesley Ann Downey, 10, John Kilbride, 12, and Edward Evans, 17, although they admitted in the mid-1980s that they had also murdered Keith.

  • Winnie Johnson, the mother of Moors murder victim Keith Bennett, cries during her son's memorial service at Manchester Cathedral. Picture date: Friday March 5, 2010. See PA story MEMORIAL Keith. Photo credit should read:Chris Gleave/Manchester Evening News/PA Wire

  • Previously unissued photo dated 8/11/2007 of a large stone with a message from the family of Lesley Molseed on the spot where her body was found high on the moors between Oldham and Ripponden. Comic book dealer Ronald Castree was today found guilty at Bradford Crown Court of the 1975 murder of 11-year-old Lesley. Picture date: Nov. 11th, 2007. See PA story COURTS Molseed. Photo credit should read: John Giles/PA Wire

  • Members of the Global Rescue Services and International Rescue Training Centre teams, dig holes in a marked out area for sniffer dogs to search an area of Saddleworth Moor in Saddleworth during privately funded search has begun for the body of Keith Bennett, the 12-year-old boy killed by Moors Murderers Ian Brady and Myra Hindley. Picture date: Sunday, March 26, 2010. See PA story POLICE Keith. Photo credit should read: Dave Thompson/PA Wire

  • Members of the Global Rescue Services and International Rescue Training Centre teams, dig holes in a marked out area for sniffer dogs to search an area of Saddleworth Moor in Saddleworth during privately funded search has begun for the body of Keith Bennett, the 12-year-old boy killed by Moors Murderers Ian Brady and Myra Hindley. Picture date: Sunday, March 26, 2010. See PA story POLICE Keith. Photo credit should read: Dave Thompson/PA Wire

  • Policemen digging at the scene where the body of Moors murder victim Lesley Downey was found. (Photo by Evening Standard/Getty Images)

  • circa 1965: Myra Hindley (1942 - 2002), left, who in 1966 was convicted on two counts of murder in conjunction with her partner Ian Brady. (Photo by Keystone/Hulton Archive/Getty Images)

  • A search is carried out on Saddleworth Moor for missing children Keith Bennett (top right), Pauline Reade (bottom left) and John Kilbride (bottom right), October 1965. All three were the victims of so-called Moors Murderers Ian Brady and Myra Hindley. (Photo by Keystone/Hulton Archive/Getty Images)

  • Mrs Ann Downey watching the police search Saddleworth moors for the body of her daughter Lesley, a victim of the Moors Murderers Ian Brady and Myra Hindley. (Photo by Keystone/Getty Images)

  • UNITED KINGDOM - OCTOBER 18: Evidence Research In The Lesley Downey Murder Case In Cheshire On October 18Th 1965 (Photo by Keystone-France/Gamma-Keystone via Getty Images)

  • 27th October 1965: Two RAF men studying a map after the discovery of the body of moors murder victim Lesley Anne Downey on the Pennines. (Photo by Peter Dunne/Express/Getty Images)

  • 25th November 1965: Teams of searchers at Doctor's Gate at Snake Pass, between Manchester and Sheffield, searching for graves after the Moors Murders. (Photo by Keystone/Getty Images)

  • December 1965: Lesley Ann Downey aged 10. She was a victim of the Moors Murderers, Ian Brady and Myra Hindley (Photo by Evening Standard/Getty Images)

  • Maureen Smith, the sister of Moors murderer Myra Hindley, with her husband David during the hearing at Hyde, Greater Manchester, 9th December 1965. They are both witnesses in the case, in which Hindley and her lover Ian Brady are to be charged with multiple murders. (Photo by Keystone/Hulton Archive/Getty Images)

  • 6th May 1966: Moors Murderer Ian Brady being taken to court in a car. (Photo by Keystone/Getty Images)

  • SADDLEWORTH, UNITED KINGDOM: In this undated handout photo supplied by the Greater Manchester Police, a police search team looks for the body of Moors murder victim Keith Bennett. Myra Hindley and Ian Brady were convicted in 1966 of the murder of 3 children. The remains of the children were then buried, by Hindley and Brady, on Saddleworth Moor. It was today announced, July 1, 2009, that the search operation for the missing remains of Keith Bennett will enter a dormant phase after Greater Manchester Police exhausted all of the avenues currently available to them. Operation Maida was launched in 2003 as a new attempt to locate the body of Keith, who was murdered by Ian Brady and Myra Hindley after going missing on 16 June 1964. (Photo by Greater Manchester Police via Getty Images)

  • SADDLEWORTH, UNITED KINGDOM: In this undated handout photo supplied by the Greater Manchester Police on July 1, 2009, Myra Hindley is seen photographed by Ian Brady at an unknown location. Myra Hindley and Ian Brady were convicted in 1966 of the murder of 3 children. The remains of the children were then buried, by Hindley and Brady, on Saddleworth Moor. It was today announced, July 1, 2009, that the search operation for the missing remains of Keith Bennett will enter a dormant phase after Greater Manchester Police exhausted all of the avenues currently available to them. Operation Maida was launched in 2003 as a new attempt to locate the body of Keith, who was murdered by Ian Brady and Myra Hindley after going missing on 16 June 1964. (Photo by Greater Manchester Police via Getty Images)

  • SADDLEWORTH, UNITED KINGDOM: In this undated handout photo supplied by the Greater Manchester Police on July 1, 2009, Myra Hindley is seen photographed by Ian Brady at an unknown location. Myra Hindley and Ian Brady were convicted in 1966 of the murder of 3 children. The remains of the children were then buried, by Hindley and Brady, on Saddleworth Moor. It was today announced, July 1, 2009, that the search operation for the missing remains of Keith Bennett will enter a dormant phase after Greater Manchester Police exhausted all of the avenues currently available to them. Operation Maida was launched in 2003 as a new attempt to locate the body of Keith, who was murdered by Ian Brady and Myra Hindley after going missing on 16 June 1964. (Photo by Greater Manchester Police via Getty Images)

  • MANCHESTER, ENGLAND - JULY 01: Winnie Johnson, 83, the mother of Saddleworth Moor murder victim Twelve-year-old Keith Bennett, is consoled by her friend Elizabeth Bond, as she watches TV coverage of Greater Manchester Police announcing that the search for his body is now entering a dormant phase on July 1, 2009 in Manchester, England. The 12-year-old was killed by Ian Brady and Myra Hindley in 1964. Greater Manchester Police said that intense scientific and manual searches of Saddleworth Moor for Keith have yielded no results and the operation has now entered a dormant stage until further evidence arises. (Photo by Christopher Furlong/Getty Images)

His refusal has caused constant heartache for Keith's mother, who has cancer and recently appealed to him to break his silence before she died.

Mrs Johnson's lawyer John Ainley, a senior partner at Oldham-based North Halliwell Ainley, said: "She has remained steadfast in her resolve that Ian Brady has held the key to this tragedy.

"Over the years she has appealed directly to Brady and through me for him to reveal where Keith's body was hidden so she could at least give her son a decent burial before she died.

"Now, she herself is ill and I am deeply concerned that the knowledge of this letter and its alleged contents may have come too late to bring her any solace.

"It would be the last tragic act of a truly harrowing story."

Ms Powell told the Cutting Edge documentary: "I received a letter and a sealed envelope which said on the front 'to be opened in the event of my death'.

"He says he doesn't wish to take his secrets to the grave and within the sealed envelope is a letter to Winnie Johnson.

"Within that is the means of her possibly being able to rest."

Brady, who has been detained for the last 25 years at Ashworth Hospital in Merseyside, was due to go before a mental health tribunal in July, but it was delayed after he suffered a seizure.

The tribunal was to consider the 74-year-old's application to be transferred to a Scottish prison and be allowed to die. He has been tube-fed since refusing food 12 years ago.

winnie johnson

Keith's mother Winnie is very unwell. Her son's body has been missing for over 47 years

Last month Mrs Johnson's solicitor said she would not be attending the hearing as it would be "too traumatic" for her. She is suffering from cancer and is being cared for in a hospice, reported to The Sun.

ian brady

'Moors Murderers' Ian Brady and Myra Hindley

Mr Ainley said his client still wanted answers from Brady.

He said: "She has only one question to ask Ian Brady, that is 'Where is my son Keith?'

"She is convinced that he could, if he wished, provide this information.

"Her one and only desire is to give her son a proper family burial during her lifetime. Nothing short of that will ever give her peace of mind."

Jackie Powell, who was appointed the murderer's legal advocate under the Mental Health Act in 1999, said Brady gave her a sealed envelope to pass on to Mrs Johnson in the event of his death.

Brady and his partner, Myra Hindley, who died in jail in 2002 aged 60, were responsible for the murders of five youngsters in the 1960s.

They lured the children and teenagers to their deaths, with victims sexually tortured before being buried on Saddleworth Moor above Manchester.

keith bennett search

A privately funded search on the rocky moors in 2010 failed to find Keith's body

Pauline Reade, 16, disappeared on her way to a disco on July 12, 1963 and John Kilbride, 12, was snatched in November the same year. Keith Bennett was taken on June 16, 1964 after he left home to visit his grandmother; Lesley Ann Downey, 10, was lured away from a funfair on Boxing Day, 1964; and Edward Evans, 17, was killed in October 1965.

Brady was jailed for life at Chester Assizes in 1966 for the murders of John, Lesley Ann and Edward.

Hindley was convicted of killing Lesley Ann and Edward and shielding Brady after John's murder, and jailed for life. In 1987 the pair finally admitted killing Keith and Pauline.

Both were taken back to Saddleworth Moor in 1987 to help police find the remains of the missing victims but only Pauline's body was found.

Documentaries commissioning editor and editor for Cutting Edge, Emma Cooper, said: "No one can verify the contents of the envelope and therefore what information it does or does not contain but, given the enormity of the implications as suggested by Brady's letter, we felt we had a responsibility to inform the family via their family liaison officer.

"Winnie's poor health was foremost in our decision-making and this is why we have decided to bring forward the broadcast of the film and make the existence of the envelope public."

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