A man who hanged himself in prison after being convicted of murdering his wife and dumping her body in Coniston Water in the Lake District could receive a posthumous pardon after the case was referred to the court of appeal.

The Criminal Cases Review Commission (CCRC) has recommended that judges review the trial of Gordon Park, who was found guilty in 2005 of killing his wife, Carol, a mother of three. It was one of the UK’s longest murder inquiries.

Carol Park had gone missing in the summer of 1976 from the family home near Barrow-in-Furness, Cumbria. Her body, trussed and weighted down, was discovered by amateur divers in 1997 in Coniston Water. The case was dubbed “the lady in the lake” murder.

Park was arrested and held on remand for two weeks after the discovery but murder charges were dropped the following January due to lack of evidence. He was rearrested in 2004, and a year later at Manchester crown court he was convicted of murder. He received a life sentence with a recommendation that he serve at least 15 years.

Park continued to protest his innocence. He appealed against his conviction, but it was dismissed in 2008. Just over a year later, he killed himself on his 65th birthday in his cell at HMP Garth in Lancashire.

His family applied on his behalf to the CCRC. On Friday, the commission announced that there was a real possibility that the court of appeal would quash the conviction in light of fresh evidence.

It cited the cumulative effect of a number of issues, including the non-disclosure of expert opinion undermining the prosecution’s assertion that Gordon Park’s climbing axe could be the murder weapon, and non-disclosure of information undermining the reliability of a prosecution witness who gave evidence of a prison confession.

The CCRC also said there was new scientific evidence showing that Park was not a contributor to DNA preserved within knots of the rope used to bind his wife’s body.

Evidence presented at the first appeal, that a rock found in the lake near Carol Park’s remains could not specifically be linked to rocks at Bluestones, the family home, has also been reassessed.

Park’s wife and children have vowed to continue the campaign to clear his name.