Police lied to the prosecutor in the Nat Fraser murder trial in order to get a conviction, it has been claimed.
Fraser was jailed for life after being convicted of murdering his wife
Fraser, 48, from Elgin in Moray, is challenging his conviction for murdering his wife Arlene in 1998.
He was found guilty in 2003 of murdering the 33-year-old, whose body has never been found.
The Court of Appeal in Edinburgh was told two officers who said they saw Arlene's rings in her house had been "hung out to dry".
Peter Gray QC, for Fraser, said the reported sightings of the engagement, wedding and eternity rings had been "extremely inconvenient" to the investigation.
At the trial, the Crown said the rings had appeared in the bathroom nine days after Arlene's disappearance and could only have been put there by Fraser.
Fraser is appealing the conviction on the grounds that the defence were not made aware of evidence of Pc Neil Lynch and Pc Julie Clark.
Alan Turnbull QC, who prosecuted the case and is now a High Court judge, gave a statement as part of a Crown Office inquiry into the Fraser case last year.
Reading from the statement, Mr Gray said: "I'm certain I was told a police officer had seen the rings at Arlene's house following her disappearance but prior to their reappearance on 7 May.
"I was told the police officer had made a mistake and what he had seen were rings from the cistern which were found sometime later.
"I have a clear recollection of being firmly reassured that the officer concerned had made a mistake and the impression that was left was that he himself acknowledged that."
Arlene Fraser's rings are seen as key pieces of evidence
Lord Turnbull could not be sure exactly who had told him this but he thought it may have been Grampian Police Detective Chief Superintendent Keith Wilkins.
Mr Gray said: "In my submission, if this information was given to Lord Turnbull by a police officer then, one way or another, lies were being told and they were being told to the advocate depute who had the responsibility to prosecute this case in the public interest and fairly.
"There is no doubt that for a variety of reasons it was very inconvenient to the police to have anybody contradicting the position regarding the rings and whether they had been there on the night Arlene Fraser disappeared.
"There is a reek about the conduct of the police and two police constables - one having recently retired having served 30 years and the other a young woman police constable - appear to be being hung out to dry to protect a conviction."
Mr Gray said it was possible that someone in the procurator fiscal service had also lied about not seeing Pc Lynch's statement until 2005.
He said: "Unpalatable though it is, in my submission, the only conclusion one can draw is that somebody lied. They lied to the inquiry and they lied to the advocate depute who was responsible for prosecuting this case.
"I'm not in a position to be more precise, but it is a legitimate conclusion to draw."
The hearing, which began before the Lord Justice Clerk Lord Gill and Lords Osborne and Johnston on Tuesday, continues and is set to last about three weeks.
The judges will deliver their written judgement some time later.
Fraser, who was ordered to serve at least 25 years of a life sentence, was released on bail in May last year.