Police investigating the disappearance of schoolgirl Tia Sharp have apologised for the delay in finding a body in her grandmother's house, blaming human error and have apologised to Tia's mother.
Commander Neil Basu said in a statement released on Saturday "it is now clear that human error delayed the discovery of the body within the house."
"On behalf of the Metropolitan Police I apologise for the distress and concern this delay will have caused. A continuing review and examination of our search processes will be undertaken to ensure such a failing is not repeated."
Christine Sharp, the grandmother of missing Tia Sharp, leaves her home accompanied by detectives
Human remains were discovered at Tia's grandmother's house in south London on the fourth examination of the property on Friday - one week after she was reported missing.
Her grandmother Christine Sharp, 46, and her partner Stuart Hazell, 37, were arrested on suspicion of murder following the discovery of the body.
Hazell was arrested in a public place - believed to be a park - in the south London borough of Merton at about 8.25pm on Friday night.
It is understood he was identified by schoolgirl Chloe Bird, 11, shortly after he bought alcohol in an off-licence.
Her stepfather Nick Keeley, 40, said she came back home and told him that she had spotted Mr Hazell.
He said he was not then aware he was wanted by officers but when his step-daughter directed him to news reports he rang the police.
"The police were here within five minutes," he told Sky News.
Tia Sharp's grandmother has been arrested on suspicion of murder
Police have not revealed where the body was discovered, but officers were seen taking a ladder into the property yesterday afternoon, sparking rumours that it may have been in the loft.
Christine Sharp's next-door neighbour Paul Meehan, 39, has been arrested on suspicion of assisting an offender.
Apologising to Tia's mother Natalie, Mr Basu explained that the first examination of the property in New Addington was not a full search.
He said mistakes were made on the second search two days later. This exercise took two hours. Mr Basu said the occupiers gave their consent to this search.
"All parts of the premises were searched including the location where a body was discovered, five days later, on Friday, August 10," he said.
The senior officer said a third visit took place on Wednesday.
"This was not a search, but the attendance of a body recovery dog to assist the investigation team in their inquiries," he said.
Neil Basu's full statement
We wish to provide further details regarding the searches that occurred in the past week at 20 The Lindens, New Addington.
The Metropolitan Police has launched a murder enquiry following the discovery of a body at the address yesterday and a number of people are in custody.
It is important that we explain more about the circumstances of the searches.
Four scene examinations were conducted of the property. The first followed immediately from the missing person report that was received on Friday 4 August. An initial visit was made to assess the situation and examine the property. This visit was not regarded or viewed as a full search of the property.
The second visit was a full search of the property with the consent of the occupiers. This was conducted on 5 August over a period of two hours. All parts of the premises were searched including the location where a body was discovered, five days later, on Friday 10 August.
An early review has been conducted and it is now clear that human error delayed the discovery of the body within the house. We have apologised to Tia's mother that our procedures did not lead to the discovery of the body on this search.
A third visit was undertaken on 8 August. This was not a search, but the attendance of a body recovery dog to assist the investigation team in their enquiries.
It is not appropriate to comment further on aspects of the criminal investigation currently being conducted but our investigation was such that it was decided that a further intrusive search needed to be undertaken - it was that search, yesterday, which resulted in the discovery.
On behalf of the Metropolitan Police I apologise for the distress and concern this delay will have caused. A continuing review and examination of our search processes will be undertaken to ensure such a failing is not repeated.