London, Aug 16 - Robin Williams was afraid that Parkinson's would stop him from cycling, which might have led him to his alcohol and drug addiction once again, it has been reported.

Tony Tom, close friend to Williams told to the Sun that the 63-year-old actor took up riding in order to quit booze, drugs and battle depression, the Mirror reported.

The 58-year-old, who owns a bike show near Williams' home in California, said that Parkinson's would have affected his ability to ride, no doubt and he could have turned back to his earlier vices if he wasn't riding and maybe that was one of the things he was thinking about.

'Mrs Doubtfire' star was found dead at his San Francisco home recently and he leaves third wife Susan Schneider and three children from his previous marriages. (ANI)