Barri White was jailed for the murder of his teenage girlfriend
The BBC's Rough Justice programme has made a new appeal for witnesses in the case of two men jailed after the murder of an 19-year-old woman.
In 2002 Barri White, of Bletchley, Bucks, was jailed for strangling his girlfriend Rachel Manning whose body was found at Woburn Golf Club in 2000.
Co-defendant Keith Hyatt, of Bedford, was cleared of murder, but found guilty of perverting the course of justice.
Rough Justice believes the convictions may be unsafe.
Both men are serving prison sentences. White, who was 21 at the time of the crime, was sentenced to life.
Hyatt, who is now 52, was sentenced to five years.
Rough Justice reporter Mark Daly told BBC News Online: "Our feeling is that this conviction was completely unsafe. The Rough Justice team have been working on this for two years and we have never been more sure.
Keith Hyatt was found guilty of perverting the course of justice
"There was a real lack of forensic evidence at the trial."
Mr Daly, who went under cover to expose racism among Greater Manchester Police trainees, said the team had found new witnesses and was keen to hear from other people who had information about the case.
Hyatt's brother-in-law Dennis Gilmartin also urged anyone with extra information on the case to contract Rough Justice.
He also said he was convinced Hyatt and White were innocent.
"I have known Keith for 30 years now. He is just not capable of this. He is too much of a coward. He would not have been able to do this and keep it to himself," he said.
"We live fairly close to Keith's parents. It is there every day whenever we see them, it is always a topic that we talk about.
"I am convinced the evidence that Rough Justice has uncovered will free them. We want them both to be cleared and we want the real murderer caught.
"We are in the process of putting together an appeal. We hope to put in the first stage of the appeal by the end of the year."