Image caption Doctors think Alex Mitchell may have suffered from the same rare heart condition as his granddaughter

The mystery of the man who was reported to have died laughing watching the comedy show The Goodies in the 1970s may have been solved by doctors.

Alex Mitchell, of King's Lynn, Norfolk, suffered heart failure after viewing the Ecky-Thump episode in 1975.

His granddaughter Lisa Corke, 23, had a near fatal cardiac arrest at home on the Isle of Sheppey, Kent, in May.

She has now been diagnosed with Long QT Syndrome which doctors think could have also caused Mr Mitchell's death.

Mr Mitchell's death after laughing for half an hour watching The Goodies made headlines around the world in 1975.

'Breathing funny'

Later his wife, Nessie, wrote to the show's stars Tim Brooke-Taylor, Graeme Garden and Bill Oddie to thank them for making his final 30 minutes so enjoyable.

Mr Mitchell's son Alex, who was 17 at the time, said: "They just thought it was a heart attack.

"After what happened to Lisa I spoke to my sister, who was with my dad at the time, and my mum... and they said it was as though my dad fainted and started breathing funny.

"Listening to how Mick [Lisa's husband] described what happened to Lisa it was almost identical symptoms.

Image caption Lisa Corke has been fitted with an internal cardiac defibrillator

"That's when the doctors put two and two together and came up with the idea that actually they think it's hereditary."

Consultant cardiologist Dr Pier Lambiase said: "You may find other members of the family that have unexplained deaths and it was put down to a heart attack at the time, but it was actually due to this condition.

"I would say given the fact that his granddaughter, I believe, had Long QT Syndrome and the circumstances of the death it would be good circumstantial evidence.

"To be absolutely certain you would have to see if there was an abnormality in the gene that causes Long QT Syndrome found in the granddaughter [that] is also evident in other members of the family, particularly the individual who passed away."

Mrs Corke was put into a medically induced coma after she suffered the cardiac arrest in May.

She said: "They [doctors] know what it is, they know that it is genetic so hopefully they'll be to find if the children have it, if my brother has it and if my father as well.

"And hopefully protect future generations in our family."

A person with Long QT Syndrome suddenly faints or passes out during exercise, or when experiencing intense emotions, such as fear.

Symptoms typically begin in young children, but may occur in newborns and can appear as late as middle age.