A Bradford man has spoken of his devastation after his father – the “Lady in the Lake” killer – was found dead in his prison cell.

Gordon Park escaped justice for nearly 30 years until he was convicted of killing his first wife Carol and dumping her body in Coniston Water in the Lake District.

He was found unconscious in his cell at HMP Garth, Leyland, Lancashire on his 66th birthday. He is believed to have killed himself.

His son, Jeremy Park, from the Wibsey area of Bradford, had campaigned to prove his father’s innocence since the end of the trial, setting up a website called freegordon. com and launching a petition.

Mr Park said he was “devastated” by his father’s death. “We are all completely devastated and still believe his innocence 100 per cent,” he said.

It was Mr Park’s belief that his father’s conviction had been a grave miscarriage of justice.

The 2005 guilty verdict brought to an end one of Britain’s most notorious unsolved murders.

Park was jailed for a minimum of 15 years and could not be considered for release for another decade. Thursday would have marked five years to the day since his conviction.

Park bludgeoned his wife to death in July 1976 and dumped her in the lake near the family home in Leece, near Barrow-in-Furness.

But unknown to him her body came to rest on an underwater ledge and was found by amateur divers 21 years later.

Park was arrested and charged but escaped conviction until fresh evidence emerged more than seven years later.

While in prison on remand in October 1997, he admitted the killing, telling fellow inmates “she deserved it” after he discovered her in bed with another man.

Police linked him to the killing through the knots used to tie up the body and a piece of Westmorland green slate used to weigh it down that matched the stone used to build the family home.

In the years following her disappearance, Park cultivated an air of respectability as a family man.

The retired schoolmaster was on holiday in France with his third wife when he was told the body had been found.

Carol was found wearing her blue baby doll night-dress, her arms were bound tightly and tape was over her eyes.

There was evidence of the wounds inflicted as she tried to defend herself.

The pair had a turbulent relationship involving wife swapping with other couples.

Carol, described at the trial as “vivacious and pretty”, had gone to live with a man she met through an Open University course but returned to the family home after losing custody of the couple’s children.

Park was not on suicide watch. It is understood he was found with a ligature around his neck and a plastic bag over his head.

A Prison Service spokesman said: “HMP Garth prisoner Gordon Park was found unconscious in his cell at 8am on Monday, January 25.

“Staff and paramedics attended but Mr Park was pronounced dead at 9.40am.

“As with all deaths in custody, the Prisons and Probation Ombudsman will conduct an investigation.”