Detectives investigating the murder of two 11-year-old schoolboys who were buried alive nearly 37 years ago have said they are pursuing new leads.
John Greenwood and Gary Miller were beaten and buried under a mattress on a rubbish tip in Whiston, Merseyside on 16 August 1980. Both died in hospital from head injuries.
Police said John Cheeseman, of Prescot, was acquitted of the murders in 1981.
Officers now want to trace three schoolboys who may have been witnesses.
Merseyside Police, which reopened its investigation last year, said the new leads follow a fresh public appeal for information.
Detectives are hoping to trace two men, who would have been boys aged between 10 and 15 in 1980, who were seen being assaulted by an older male outside Whiston Health Centre weeks before the murders.
They also want to speak to another man, then also a boy aged 10 to 15, who was called either 'Duffy' or 'Cuffy'.
He was seen with another boy at the rear of the Labour club in Whiston on the day John Greenwood and Gary Miller were found by a dog walker at the disused colliery.
The victims' fellow pupils at Halsnead junior school and anyone who attended the 28th St Helens (1st Whiston) Scout Group (latterly known as the 2nd Knowsley Scout Group) in 1980 are also being asked to come forward.
Det Ch Insp John Middleton stressed that the murdered boys' families have had to "live with the agony of losing their children ever since".
He added: "I would ask people to cast their minds back to 1980 and see if they can remember anything which could assist us with this investigation.
"The families of both boys quite rightly want justice and I am sure the people of Whiston, and Merseyside as a whole, would want to help them get that."