A documentary on the life of Moors murderers Ian Brady and Myra Hindley could shed new light on the bid to find the remains of victim Keith Bennett.
The ITV programme Brady and Hindley: Possession is due to feature black and white photographs taken by the duo during their trips to the moors. The documentary is due to be shown next month, after a legal hearing - which begins on Monday - in which Brady effectively seeks the right to die.
Keith's final resting place remains a subject of mystery. The 12-year-old was abducted and murdered by Brady and Hindley in 1964 and is the only one of the five young victims whose body has never been traced despite police accompanying Brady on two unsuccessful trips to the moors in the 1980s in an effort to discover the remains.
The documentary raises questions about whether Keith's body may have been buried nearly 40 miles away from Saddleworth Moor - the focus of the search for his remains up to now. His mother, Winnie Johnson, died in August last year without having fulfilled her wish of being able to mark her young son's grave.
The programme suggests the photographs taken by Hindley and Brady could be "grave markers" during their killing spree and show a Staffordshire beauty spot called Ramshaw Rocks.
The documentary also features rare audio footage from Hindley in custody and is based on Duncan Staff's book The Lost Boy, an investigation into the murders, which is due to be republished next week.
Mr Staff, who produced the programme, said: "The documentary looks at the relationship between Hindley and Brady during the murders and their manipulation of evidence. I think it will raise one or two important questions about the investigations which have yet to be solved."
Brady, 75, who remains in prison after being locked up for life, had been urged by police to "at last do the decent thing" and finally tell Keith's family where he buried him so he can be given a Christian burial.
Brady and Hindley's other victims were Pauline Reade, 16, who disappeared on her way to a disco on July 12 1963; John Kilbride, 12, who was snatched in November the same year; Lesley Ann Downey, 10, who was lured away from a funfair on Boxing Day 1964, and Edward Evans, 17, who was axed to death in October 1965. Hindley died in jail in 2002 aged 60.
A legal hearing will begin on Monday at which Brady - who has been on hunger strike for more than a decade and is tube-fed - will ask to be transferred from Ashworth hospital in Merseyside to a prison in Scotland, where they are not force-fed. A move would effectively allow Brady to starve himself to death, without intervention. The hearing, at Ashworth but relayed to a court in Manchester, is expected to last for around a fortnight.