LONDON (Reuters) - Cult graffiti artist Banksy has been given a dose of his own anarchic medicine -- one of his best-known works has been defaced with a paintball gun.
The picture, on the side of a sexual health clinic in his home town of Bristol, shows a naked man hanging from a window ledge as a jealous lover scours the horizon and an adulterous partner looks nervously on.
"There are about five or six blue (paint) splodges on the piece," said a spokeswoman for Bristol City Council.
"I think he (Banksy) has challenged a councilor to clean it, because the council once said it could clean off the original graffiti for a fee of 10 pounds," she said.
In 2006, the council asked the public to vote on whether the mural should stay or be removed, with 93 percent of respondents saying it should stay.
Works by the anonymous English artist can fetch hundreds of thousands of pounds and are popular with some of the world's biggest stars.
An exhibition of his work opened in Bristol 10 days ago. It runs for 12 weeks.
Reporting by Stefano Ambrogi; Editing by Steve Addison