To those who knew him, or thought they knew him, he was a cerebral, fun-loving gadfly who hosted boozy gatherings for Hollywood's political conservatives. David Stein brought right-wing congressmen, celebrities, writers and entertainment industry figures together for shindigs, closed to outsiders, where they could scorn liberals and proclaim their true beliefs.

Over the past five years Stein's organisation, Republican Party Animals, drew hundreds to regular events in and around Los Angeles, making him a darling of conservative blogs and talkshows. That he made respected documentaries on the Holocaust added intellectual cachet and Jewish support to Stein's cocktail of politics, irreverence and rock and roll.

There was just one problem. Stein was not who he claimed. His real name can be revealed for the first time publicly – a close circle of confidants only found out the truth recently – as David Cole. And under that name he was once a reviled Holocaust revisionist who questioned the existence of Nazi gas chambers. He changed identities in January 1998....