The documentary says photos like this may act as grave markers
Police investigating the whereabouts of the body of a Moors murder victim say photos kept by Myra Hindley have not led them to a burial site.
A BBC documentary claims the pictures, originally seized after their arrest in 1965, could identify twelve-year-old Keith Bennett's grave.
Keith went missing 40 years ago as he walked to his grandmother's Manchester home. His body has never been found.
But Greater Manchester Police say they have not identified any location from the pictures.
The documentary, The Moors Murder Code, claims police began looking at certain photographs after they were handed letters Hindley wrote to her mother Nellie from jail.
They showed the importance she and Brady attached to the photos - originally seized by police after their arrest in 1965.
Police stored copies of them before returning the originals to the convicted killers.
The author of the documentary, Duncan Staff, says after Hindley's death he was handed 200 pictures that were in her possession as well as her unpublished autobiography.
In it, Hindley reveals that she and Brady were using pictures to record the sites of their victims' graves.
But a spokeswoman for Greater Manchester Police said police had looked at the photographs but were finding it difficult to identify any specific location.
According to the documentary, one image showing Myra Hindley clutching her collie dog bears a resemblance to a photo used as a "marker" for the grave of another victim 12-year-old John Kilbride.
But the police spokeswoman said: "The work that has been done on the photograph has proved to be fruitless.
"Geological experts... have said the location of the picture cannot be identified because of the lack of detail."
At their trial in 1966, Brady and Hindley were convicted of the murders of Lesley Ann Downey, 10, and Edward Evans, 17. Brady was also found guilty of murdering John Kilbride, 12.
Although they were suspected of killing 16-year-old Pauline Reade and Keith Bennett, there was no evidence. But in the 1980s, Greater Manchester Police began a new investigation.
Interviewed behind bars, Brady and Hindley finally admitted to the crimes. They were taken separately to Saddleworth Moor to try to find the bodies.
Eventually, the police managed to locate the remains of Pauline Reade, but despite many weeks of digging, they were unable to find the body of Keith Bennett.
The documentary also reveals that after discussions with staff at GCHQ spy centre, detectives last year employed code-breakers to uncover hidden messages Brady and Hindley sent to each other in poems and letters.
But their secret communication provided no clues about the location of Bennett's body and police continue to keep the case open.
The Moors Murders Code was broadcast on BBC Two at 2100BST on Wednesday.