During its production, when The Hangover was just a comedy potboiler with a cast of relative unknowns, the actors were happy to share the screen with the convicted rapist Mike Tyson.
Since it became a $500m box-office behemoth, however, they appear to have altered their policy on potential co-stars. Director Todd Phillips has confirmed that Mel Gibson will no longer appear in The Hangover 2, following protests from some of his cast and crew.
Earlier this week, it was revealed that Phillips had asked Gibson to take a cameo role as a tattoo artist in the blockbuster sequel. "I thought Mel would have been great in the movie," Phillips said on Thursday, claiming his decision to cast Gibson was endorsed by Jeff Robinov, the president of Warner Bros. "But I realise film-making is a collaborative effort, and this decision ultimately did not have the full support of my entire cast and crew."
Gibson, 54, has been subject to a series of damaging revelations about his private life. His reputation first nosedived in 2006, when the actor-director was arrested for drink-driving in Los Angeles. He addressed a female police officer as "sugar tits", and informed her colleagues that "the Jews are responsible for all the wars in the world". He subsequently issued an apology for his "despicable" remarks, blaming the incident on his alcoholism.
After a five-year break from acting, Gibson returned to the screen this year in Edge of Darkness. But his comeback was curtailed when audio recordings of phone calls to his ex-girlfriend Oksana Grigorieva were leaked to the internet. The tapes, in which Gibson is heard using racist terminology and calling Grigorieva a "whore", were accompanied by allegations of domestic abuse against Grigorieva and the couple's baby daughter.
In July, the actor was dropped by his talent agency, William Morris Endeavor. The release of his latest film, The Beaver, has been delayed indefinitely, despite its director, Jodie Foster, describing it as "one of his most powerful and moving performances". (Gibson plays a man who converses with a beaver-shaped hand puppet.) The now-cancelled comic role in The Hangover 2 was seen as a chance to sew together the tatters of his profile.
Mike Tyson's performance in the original film, about an eventful stag weekend in Las Vegas, is thought to have aided the former boxer's public rehabilitation following his 1992 rape conviction. Tyson, playing himself, sprinkled stardust over a few uproarious scenes. But The Hangover was so successful that it made stars of lead actors Bradley Cooper, Ed Helms and Zach Galifianakis; its sequel won't need celebrity cameos to carry it to box-office glory.
It is thought Galifianakis – also the star of Phillips's latest film, Due Date – may be behind the protest. In a podcast interview to promote Due Date, he explained that, as an actor, "you don't have a lot of control; you just show up and vomit your lines out. I'm not the boss. I'm in a deep protest right now with a movie I'm working on, up in arms about something... It's very frustrating."
Galifianakis also claimed to have declined roles in the past for moral reasons. He did, however, take part in The Hangover's most celebrated scene, in which Tyson punches his character in the face as punishment for stealing his pet tiger.