British comedian Russell Brand fired back at claims he was drunk on set and sexually assaulted a former co-star during the filming of Arthur in 2010. In newly filed court docs obtained by RadarOnline.com, the actor said the entire lawsuit is premised on the false accusation that he was “visibly intoxicated” while shooting the movie. As we previously reported, the New York complaint filed by an anonymous “Jane Doe” alleges that on July 7, 2010, Brand was under the influence and “smelled of alcohol, and was carrying a bottle of vodka.” “He then exposed his penis to me on set and in full view of …