A CONVICTED drug dealer died from natural causes while awaiting trial for his role in one of Europe's largest dog fighting rings, an inquest heard.

John Parker, 44, known in the dog fighting world as "Oddjob," was found collapsed in his cell at Lincoln Prison in April last year after suffering a heart attack.

Four other people including Parker's wife Claire, also 44, were later jailed following an investigation by the BBC's Panorama programme.

The RSPCA launched a probe after being tipped off about a 24- minute fight between two dogs in a converted pit at the isolated property.

When the couple's cottage in Kexby, near Gainsborough, was searched three scarred pit bull terriers and dog fighting gear were found.

Nearly £10,000 worth of cannabis and £4,000 in cash was discovered hidden in a kennel during the joint RSPCA and police raid.

Parker, described in a previous court case as a "major figure in dog fighting", was jailed for 30 months for the drugs offences in December 2008.

But he died four months later in Lincoln's Victorian jail while awaiting trial for his part in the dog fighting syndicate.

One of the ring had told an undercover Panorama reporter his pitbull Pablo was in a fight at the house refereed by Parker.

Other members of the ring were found to have links to a gang in Northern Ireland, with paramilitary connections. They also attended fights as far away as Finland.

An inquest jury at Lincoln Crown Court deciding how Parker died yesterday returned a verdict of natural causes.

They heard the 16 stone inmate was discovered unresponsive in his cell only minutes after working out in the prison gym for the first time. Despite the efforts of prison staff and paramedics, he was declared dead at the scene.

The inquest was told Parker, who suffered from mild asthma, should not have been allowed in the gym because he had not undergone a formal induction – but he managed to obtain a pass from another inmate.

Prison officer Christopher Bright said while he had asked a gym orderly to make up an access card for the obese smoker, he should not have been able to visit the facility until he had completed the induction and a fresh health questionnaire.

"I said I would bring him the paperwork, but if he knew he had a problem with asthma then it would have to be checked with the nurses that he was okay to go to the gym," he said. "But I never got round to taking him the forms.

"I certainly never asked for the orderly to get the card signed and give it to him."

The inquest was attended by Parker's widow, Claire. Concluding the proceedings, West Lincolnshire coroner Stuart Fisher told her: "I appreciate it must be very difficult for you."