The family of a man serving life for murdering his ex-girlfriend are preparing for a last-ditch legal attempt to have key forensic exhibits retested.
Kevin Nunn was convicted in 2006 of the murder of Dawn Walker after her partially clothed body was found on the bank of the River Lark in Suffolk on February 4 2005.
Nunn's legal team are trying to force Suffolk Police to give them access to key forensic evidence linked to the case that they said was not properly examined at the time.
This includes sperm that was found on Miss Walker's body, from which the original investigators were unable to get a full DNA profile.
Nunn's sister Brigitte Butcher said: "Why would Kevin put himself out there asking for all of these tests if there was any way he was guilty? We're asking them to look at this again because the evidence at the time was fragile and there were so many assumptions made."
He admitted to police that he had a key to Miss Walker's house that she was unaware of, but despite his honesty was made "the fall guy", his sister claimed.
Mrs Butcher added: "Why would you hand a key over if you had been storing a body in the house? All he did was try and tell the truth, and because he didn't have an alibi, he lived alone, he was the fall guy.
"If there is any glimmer of doubt people should have the right to review the evidence again."
Nunn was denied permission to appeal his conviction in 2007, and in 2012 his attempts to get Suffolk Police to grant access to key exhibits were also turned down.
On Thursday his lawyers will take the battle to get the evidence retested to the Supreme Court.
Miss Walker, 37, from Fornham St Martin, near Bury St Edmunds in Suffolk, left Nunn for a man with whom she had previously had a relationship, and prosecutors claimed he was overcome with jealousy and killed her.
Describing his original murder trial, nurse Mrs Butcher, who lives in Norfolk, said: "There was character assassination in the courtroom that he was lying and he was jealous.
"Perhaps he was jealous but not to the extent that he would kill Dawn. He had no previous convictions, he had only ever had a parking ticket.
"There wasn't one piece of evidence against Kevin. Poor Dawn's death was a hideous ordeal that she went through, but there wasn't anything against Kevin forensically."
The mother-of-two said her brother's fight to prove his innocence is what keeps him going.
"Obviously he's not the same person, none of us are. We are all from a working class family and we believed in justice and the police and due process.
"We all believed that coming out of the trial Kevin would have walked free. We all naively thought that was going to happen. Now I've got no faith in the justice system.
"It's awful to see him and to have to leave him there. He is relying on us out here to do the right thing. His life stopped on March 14 2005 when he was arrested and charged with murder, and then convicted and given a 22-year sentence for something he hasn't done. The truth keeps him going.
"We've just got to wait, we've got to remain positive. All we want is the truth."
Louise Shorter from Inside Justice, the investigative unit of prison newspaper Inside Time, said if Nunn's application is rejected, other inmates will be left without hope of challenging their convictions.
The former television producer, who worked on the BBC's Rough Justice series, said: "Over the years, scores of wrongly convicted persons were cleared after lawyers, journalists, broadcasters, relatives and campaigners re-examined crucial case material and information.
"Eighteen innocent persons were exonerated following BBC Rough Justice investigations. In most of these cases, we had access to crucial material held by the police and prosecution.
"If the Nunn judgement stands, more innocent people will remain in prison with no hope of ever finding evidence to overturn their convictions."