Aaron Barschak, the self-proclaimed 'comedy terrorist', has been convicted of causing criminal damage for throwing red paint over Turner Prize nominee Jake Chapman and one of his paintings.
Barschak pleaded not guilty
Barschak, 37, from Golders Green, north London, claimed he was collaborating with the artist and denied causing criminal damage at the Modern Art Oxford gallery on 30 May.
The incident happened during a private talk about Mr Chapman's work to the patrons of the gallery.
The stand-up comedian - who gatecrashed Prince William's 21st birthday party in June dressed as Osama Bin Laden - was found guilty after a one-day trial at Oxford Magistrates Court.
District Judge Brian Loosley called the 37-year-old a publicity seeker.