The Independent Police Complaints Commission (IPCC) could formally investigate the role played by Britain's most senior police officer, Sir Bernard Hogan-Howe, in the Hillsborough disaster.
It said it had received a complaint about Metropolitan police commissioner Hogan-Howe, who was on duty at Sheffield Boys' Club where families waited for news of loved ones on the day 96 Liverpool football fans were killed in 1989.
The IPCC is looking at the treatment of relatives in the immediate aftermath of the disaster and how officers managed the task of informing them.
The watchdog contacted the family of 14-year-old victim Adam Spearritt, following reports his name was wrongly read out on a list of people believed to alive by an unidentified police officer at the club.
In a statement, the IPCC confirmed it had received a complaint about Sir Bernard - an inspector at South Yorkshire Police at the time of the Hillsborough disaster - which had been passed to the Mayor's Office for Policing and Crime.
"The Independent Police Complaints Commission can confirm it has received a complaint about Sir Bernard Hogan-Howe in relation to his role at Hillsborough," it said.
Hillsborough Tragedy
Hillsborough(01 of18)
Open Image ModalLIVERPOOL SUPPORTERS ARE HELPED AFTER BEING CRUSHED AGAINST THE SAFETY (credit:PA)
Hillsborough(02 of18)
Open Image ModalFan in despair after the Hillsborough Disaster (credit:PA)
Hillsborough Tragedy(03 of18)
Open Image ModalFans leave the ground after the disaster (credit:PA)
Liverpool v Nottingham Forest - Hillsborough(04 of18)
Open Image ModalOne of the fans who came to see the semi -final between Nottingham Forest & Liverpool, is led away after surviving the disaster (credit:PA)
Hillsborough Tragedy(05 of18)
Open Image ModalThe injured are carried away on boards by fans who came to see a game of football (credit:PA)
Hillsborough(06 of18)
Open Image ModalFans try to get away from the crush of the crowd as they pour into the ground (credit:PA)
Hillsborough papers published(07 of18)
Open Image ModalFile photo dated 15/04/1989 of Liverpool fans trying to escape severe overcrowding during the FA Cup semi-final football match between Liverpool and Nottingham Forest at Hillsborough. The families of 96 people killed in the Hillsborough tragedy will see thousands of official documents relating to the disaster for the first time today. (credit:PA)
Hillsborough papers published(08 of18)
Open Image ModalFile photo dated 15/04/1989 of a Liverpool fan at Hillsborough after their FA Cup semi-final football match against Nottingham Forest. The families of 96 people killed in the Hillsborough tragedy will see thousands of official documents relating to the disaster for the first time today. (credit:PA)
Hillsborough papers published(09 of18)
Open Image ModalFile photo dated 22/10/11 of a banner in memory of those who died in the Hillsborough tragedy at Anfield, as the families of 96 people killed in the Hillsborough tragedy will see thousands of official documents relating to the disaster for the first time today. (credit:PA)
Hillsborough papers published(10 of18)
Open Image ModalFile photo dated 15/04/2011 of a Hillsborough banner at Anfield, as the families of 96 people killed in the Hillsborough tragedy will see thousands of official documents relating to the disaster for the first time today. (credit:PA)
Hillsborough papers published(11 of18)
Open Image ModalFile photo dated 15/4/2009 of a hans paying tribute at the Hillsborough Memorial in Liverpool. he families of 96 people killed in the Hillsborough tragedy will see thousands of official documents relating to the disaster for the first time today. (credit:PA)
Liverpool Prepares For Hillsborough Disclosure Day(12 of18)
Open Image ModalLIVERPOOL, ENGLAND - SEPTEMBER 10: The Hillsborough memorial is covered with tributes at Anfield Stadium, the home of Liverpool Football Club on September 10, 2012 in Liverpool, England. On Wednesday relatives and friends of the 96 victims of the Hillsborough football stadium tragedy in Sheffield on 15 April 1989 will see the full disclosure of all documents relating to the disaster when they are made public at Liverpool's Anglican Cathedral. (Photo by Christopher Furlong/Getty Images) (credit:Getty Images)
Liverpool Prepares For Hillsborough Disclosure Day(13 of18)
Open Image ModalLIVERPOOL, ENGLAND - SEPTEMBER 10: The Hillsborough memorial is covered with tributes at Anfield Stadium, the home of Liverpool Football Club on September 10, 2012 in Liverpool, England. On Wednesday relatives and friends of the 96 victims of the Hillsborough football stadium tragedy in Sheffield on 15 April 1989 will see the full disclosure of all documents relating to the disaster when they are made public at Liverpool's Anglican Cathedral. (Photo by Christopher Furlong/Getty Images) (credit:Getty Images)
Hillsborough papers to be published(14 of18)
Open Image ModalThe front cover of 'With Hope In Your Heart' written by 51 year old Chris Whittle who lives in Burnley. (credit:PA)
Hillsborough papers published(15 of18)
Open Image ModalHillsborough Family Support Group members during a press conference at Liverpool's Anglican Cathedral after the release of previously unpublished papers realting to the Hillsborough disaster. (credit:PA)
Hillsborough papers published(16 of18)
Open Image ModalHillsborough Family Support Group members Jenny Hicks (left) and Margaret Aspinall (right) during a press conference at Liverpool's Anglican Cathedral after the release of previously unpublished papers realting to the Hillsborough disaster. (credit:PA)
Hillsborough papers published(17 of18)
Open Image ModalHillsborough Family Support Group member Margaret Aspinall, the mother of Hillsborough victim James Aspinall, during a press conference at Liverpool's Anglican Cathedral after the release of previously unpublished papers realting to the Hillsborough disaster. (credit:PA)
Hillsborough papers published(18 of18)
Open Image ModalHillsborough Family Support Group member Trevor Hicks speaks during a press conference at Liverpool's Anglican Cathedral after the release of previously unpublished papers realting to the Hillsborough disaster. (credit:PA)
"This complaint has been passed onto the Mayor's Office for Policing and Crime (MOPC) for recording as required by the complaints process.
"The MOPC is responsible for deciding whether complaints against the commissioner should be recorded and whether they should be referred to the IPCC. However in this instance the IPCC expects the matter to be recorded and referred."
A Met Police spokesman said: "As has been made clear, the commissioner will co-operate fully with any inquiries from the IPCC."
Fresh inquests into the deaths of the Hillsborough victims who died during or after the 1989 FA Cup semi-final are due to start in Warrington on March 31.
The disaster took place at Sheffield Wednesday's Hillsborough stadium on 15 April 1989 when fans were crushed to death at the match between Liverpool and Nottingham Forest.
The original inquest verdicts of accidental death were quashed in December, three months after the damning findings of Hillsborough Independent Panel report were released.
The watchdog has also written to former prime minister Sir John Major after he apologised to Hillsborough families for failing to order an inquiry when he was in power.
The ex-Tory leader claimed in a speech last month that police had ''pretty strong views'' that there was no need for a report into the disaster.
The IPCC said it has written to Sir John to establish further details and determine whether it should be incorporated into its inquiry.
The watchdog added: "At this stage we are investigating the processes and if, through that work, we identify individuals whose actions should be formally investigated then we will pursue that."
A spokesman for Sir John said he was unavailable for comment but confirmed his office had not yet received a letter from the IPCC.
More than 2,000 police notebooks have been located after a search of archive storerooms and 118 have been handed in by South Yorkshire Police officers who were on duty at Hillsborough, the IPCC said.
A witness appeal had prompted responses from 1,500 people and generated more than 750 lines of inquiry for investigators.
After interviews with serving and retired police officers, the IPCC said the number of police accounts of the day which had been amended stood at 240, up from the 164 originally identified by the Hillsborough Independent Panel.
It said 101 interviews had been carried out with officers.
Of the nine Hillsborough officers who declined to be interviewed, none are senior or suspected of criminal offences, the IPCC said.
Last year a damning report by the Hillsborough Independent Panel found that South Yorkshire Police orchestrated a cover-up, falsified documents and blamed innocent supporters in the aftermath.
The lives of 41 fans could have been saved, the report concluded, as it cleared supporters of any wrongdoing or blame for the disaster.