Police today said they had exhausted all avenues in the search for the body of the Moors murders victim Keith Bennett.
Detectives said the Saddleworth moor search for the remains of the 12-year-old, who disappeared as he walked to his grandmother's house more than 45 years ago, had been unsuccessful. The operation began last year.
The case is now being classified as dormant by Greater Manchester police.
The remains of Bennett, the last untraced victim of Ian Brady and Myra Hindley, are now unlikely to be found unless there is a major scientific breakthrough or significant piece of new evidence.
Detectives launched the latest search of the moors, near Oldham, Lancashire, last year, using photos taken by the killers.
They were matched against aerial pictures and chemical testing equipment, sniffer dogs and metal detectors were used.
Bennett was killed by Brady and Hindley after disappearing from a Manchester street on 16 June 1964.
Hindley died in prison eight years ago after a long and unsuccessful campaign to be freed.
Brady, along with his former lover, was convicted of murdering Lesley Ann Downey, 10, Edward Evans, 17, and John Kilbride, 12.
He was transferred to the Ashworth high security hospital in 1985 and two years later finally confessed to murdering 16-year-old Pauline Reade and Bennett.
Police took both killers back to the moors separately to help search for bodies in the 1980s.
Brady has refused to co-operate with police in their search for Bennett.
Greater Manchester police said the decision to reclassify the case had been taken "with regret".
Winnie Johnson, Keith's 75-year-old mother, said: "I just want Keith found.
"I will never give up as long as I have breath in my body – not just for me but for my family and all of those around me. What Brady has done, and continues to do, is cruel."
Detective Chief Superintendent Steve Heywood, the head of the force's serious crime division, said: "The Moors murders have cast a long and dark shadow over the history of our region.
"We had all hoped that we would find the body of that little boy who was taken so cruelly away all those years ago and finally allow his family to lay him to rest.
"Sadly, we have not found his body ... we reluctantly have to say that, for now, we have exhausted all of the avenues available to us."
He said Brady held the key to finding Bennett's body.
"One act of humanity would help Winnie find some peace and allow her to give her son the burial she so desperately wants," he said.
"We are very disappointed we have not located Keith's remains, but we will never close this case and remain open to pursuing any new lines of inquiry."
