Detectives have reopened an investigation into the murder of two 11-year-old boys who were beaten and buried alive on a rubbish dump in Liverpool 36 years ago.
John Greenwood and his best friend Gary Miller went missing in Whiston, Merseyside, in August 1980 after they went out to play after dinner on a sunny summer evening.
A man out walking his dog found the boys, partially buried under a mattress, and called police.
The boys were rushed to hospital and underwent surgery but John died in the early hours of the following morning and Gary died a few days later.
Both suffered fractured skulls and never regained consciousness. Police believed their killer banged their heads on the ground.
A milkman, John Cheeseman, confessed to the crime while in police custody but was acquitted at Liverpool Crown Court in May 1981.
His lawyers pointed out he was mentally deficient and should have had a solicitor or guardian present when he was interviewed by police.
The Sunday Times said detectives had unearthed allegations pointing towards Robert Fisher, who died in 1991, aged 73.
His wife, Ethel, reportedly committed suicide in 1999 after telling friends she could no live with the guilt of knowing her husband had killed the boys.
Detective Chief Superintendent Paul Richardson: "We are particularly interested in talking to anyone who may have seen a man with three young boys, aged between 12 and 14 years, near to the church hall on Dragon Lane, Whiston, between 6.45pm and 7.20pm on Saturday 16 August 1980.
"Two of the boys who were seen with the man were stood on the wall of the church hall and one was in the grounds of the church hall.
"Were you one of the three boys? If so please come forward and talk to us."
He said the failure to reopen the case previously was "completely unacceptable".
John Greenwood's sister Deborah told the Liverpool Echo: "Losing the boys in such an horrific way was devastating for both families and has been heartbreaking to cope with.
"The fact that no-one has been convicted for their murders has made it so much harder.
"For 36 years we have lived with the frustration and the fear that we could be sitting next to their killer on a bus, or walking past them on the street.
"The murder of a child in a family causes so much pain to everyone, the very least we deserve is to find the evil person that did this and put them behind bars.
"Both the Greenwoods and the Millers are united in their fight for justice and we are supported by family and friends and local people."
More than 2000 people have joined a Facebook page to show their support for justice for the boys.
Detectives from Merseyside Police's Serious Crime Review Unit want to speak to anyone who saw the boys on Saturday, August 16 1980 or has any information about the case.
The rubbish dump in Whiston, near Knowsley, where the boys' bodies were found has since been landscaped and is now known as Stadt Moers Park, after Knowsley's twin town in Germany.