Sir Billy Connolly has put himself forward to become a stem cell research “guinea pig” as part of efforts to find a cure for Parkinson’s disease.

The Glasgow-born comedian was diagnosed with the illness five years ago.

He says he has been in touch with scientists at Harvard University in Massachusetts, US, whose stem cell institute is a key leader in research into Parkinson’s.

The 75-year-old told the Mail on Sunday: “I’ve spoken to guys working on it at Harvard and told them I’ll be a guinea pig for them.

“I think they are going to take me up on that.”

Sir Billy was diagnosed with prostate cancer – for which he had successful surgery – in the same week he was told he had Parkinson’s, in 2013.

The disease is the first thing he thinks about every day, he told the newspaper.

He added: “The thing that I find hardest is coming to grips with the fact that it’s never going to go away.”