Three senior judges have rejected a posthumous appeal against the conviction of Gordon Park, the so-called "Lady in the Lake" killer.
The body of his wife Carol was found in Coniston Water in the Lake District in 1997, 21 years after she disappeared.
Park was convicted of murder in 2005 and killed himself in prison in 2010.
The case, brought by his son, Jeremy Park, was dismissed by the Court of Appeal, which said there was "no reason to doubt the safety of the conviction".
The family said it was "disappointed" with the decision.
The appeal was referred to the court by the Criminal Cases Review Commission (CCRC) and argued the Crown Prosecution Service did not disclose evidence in the trial which would have undermined the credibility of a prison inmate, who claimed Park had confessed to his wife's murder.
It also cast doubt on the prosecution's claim Park's ice axe might have been the murder weapon, citing two dental experts who agreed it could not have caused injuries to his wife's teeth.
However, the court said the evidence in the case was "very strong".
Mr Justice Sweeney, who delivered the ruling, said: "We have no doubt as to the safety of the conviction."
Analysis - Danny Shaw, BBC home affairs correspondent
It's a tough task to overturn a conviction, especially when an appeal has already failed, as it did in this case in 2008.
This most recent appeal relied on new expert evidence and the prosecution's failure to disclose certain material.
The three judges weighed it up carefully but Mr Justice Sweeney's meticulous 81-page ruling is crystal clear that it didn't come close to denting the "very strong" circumstantial evidence against Park.
It will surely prove to be the final word on the murder of the Lady in the Lake.
Mrs Park was 30 when she vanished from Leece, near Barrow-in-Furness, in July 1976.
Her husband did not report her disappearance for six weeks, claiming she had gone to live with another man.
The mother of three's remains were found by amateur divers in 1997, wrapped in bags and tied with rope.
Park was charged with her murder, but the case was dropped in 1998.
However, following fresh evidence he was found guilty at Manchester Crown Court in 2005, and sentenced to life with a minimum term of 15 years.
Park, who always maintained his innocence, hanged himself in his cell on his 66th birthday in January 2010.
CCRC lawyers told a hearing in November 2019 that prosecution lawyers had failed to share evidence with the defence at Park's trial, casting doubt on the safety of his conviction.
However, the Court of Appeal dismissed the case, citing the length of time it took Park to report his wife missing, his failure to contact friends or family about her, and that he made no attempt to check the joint bank account or put a stop on it.
He had also failed to make the usual child care arrangements at the beginning of term when his wife, a teacher, would have gone back to work.
There was also evidence that Park, the owner of a sailing dinghy, had skills in all the sailing knots used to tie the body, and knowledge of the area of the lake where the body was dumped.
A statement issued on behalf of his family said: "The family, friends and supporters of Gordon Park, and Carol Park's children, are disappointed with today's decision.
"Having exhausted all options, we are now left without the closure we were all hoping for.
"The judgment marks the end of our fight to clear his name."