Comedian Sacha Baron Cohen could not sit down for three days after an accident while bleaching all his body hair, it was reported today.

Rash decision: Sacha Baron Cohen's gay disguse backfired

He was said to have come out in a burning rash after suffering an allergic reaction to the chemicals, including hydrogen peroxide. The incident happened while he was filming Bruno, a "mockumentary" about a camp fashion reporter.

A source said: "Sacha is committed to as much realism as he can muster in his film.

"He'd heard that all-over hairlessness is a popular trend in the gay community, so he thought he'd bleach all his hair so it looked invisible." Baron Cohen, 37, made an emergency doctor's appointment and was given medication to counter the rash. He suffered no long-lasting ill effects.

But the source added: "It was so severe around a certain part of his anatomy he couldn't sit down for three days." Bruno is due to hit cinemas on 10 July. In it, his character crashes the Paris and Milan fashion weeks and a rally to ban gay marriages.

Bruno follows Baron Cohen's 2006 comedy hit, Borat, in which he played a Kazakhstan reporter trying to understand the American way of life.

Both Bruno and Borat were sketch characters in Baron Cohen's TV series, Da Ali G Show.