Comedian Billy Connolly has volunteered to be a "guinea pig" in the bid to find a cure for Parkinson's disease.

The Glasgow-born star, who was diagnosed with the illness five years ago, has offered himself for experimental stem cell research with Harvard University.

The research, which involves laboratory engineered stem cells being injected into the part of the brain affected by the condition, would form part of the first experimental treatments on humans.

Sir Billy, 75, told the Mail on Sunday: "Researchers are making progress on curing the disease.

"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."

Last year, researchers announced that primates with symptoms of Parkinson's regained significant mobility after Pluripotent Stem (iPS) cells were inserted into their brains.

Kyoto University in Japan has already began the first human trial involving seven participants.

The two-year experiment follows collaboration from around the world, including the Harvard Stem Cell Institute, a leader in the field.

Sir Billy, who was diagnosed with Parkinson's and prostate cancer in the same week in December 2013, also revealed the impact the disease has had on his life - including stopping him from driving and performing.

"It occupies a lot of my thinking time every single day," he said. "The thing that I find hardest is coming to grips with the fact that it's never going to go away.

"Everything that has ever been wrong with me in the past always went away, eventually. It was either operated on or it cured itself. This isn't going anywhere: in fact, it's going to get worse."

He added: "I've learned to take it easier and to look out for when the shaking starts. I'm coping with it and I'm hanging in there."