Stephen John Slater (47) was jailed indefinitely at Cambridge Crown Court in April 2008 after a jury convicted him of rape and two counts of sexual assault.

Slater, of Wellington Terrace, Wisbech, was accused of attacking the 18-year-old at the Wisbech home he shared with his wife, Sybil, in October 2006.

Sybil Slater, of the same address, was given a community order after the jury found her guilty of sexual assault and aiding and abetting rape.

But Slater was back in court when his lawyers launched a legal battle before three top judges in London to overturn his convictions.

A new witness had come forward since Slater's sentencing, who would tell the court that the victim had admitted crying rape in order to get money, the judges were told.

That would seriously undermine the credibility of the complainant as a witness and cast doubt on the safety of Slater's convictions, Lord Justice Pitchford, Mr Justice Penry-Davey and Judge Peter Beaumont QC were told.

But lawyers for the Crown said the evidence should not be allowed to be heard at the Court of Appeal, since it was "incapable of belief".

Slater had never before claimed that he had had consensual sex with the woman, instead claiming throughout that he had not had any contact with her.

And the witness could have come forward at any point and told police, the prosecution or defence lawyers that the woman had admitted she lied.

Lord Justice Pitchford said that, as the witness had not appeared at court and was proving difficult to contact, it appeared that he was "avoiding" Slater's legal team.

And Mr Justice Penry-Davey continued: "Considering all the aspects of the matter, in our judgment this application falls at the first hurdle.

"We do not consider that this statement is capable of belief.

"In those circumstances, it cannot and would not afford any grounds for allowing this appeal and it would be entirely inappropriate to admit it in evidence."

Slater's appeal was "hopeless", he concluded.