If you want to hear the dirtiest joke ever told... don't bother heading for your local AMC megaplex reports Newsweek.

The theater chain has decided not to show the buzzed-about documentary "The Aristocrats" on any of its 3,500-plus screens. The $20,000 unrated film features 102 of the world's most famous comedians, each telling their interpretations of the same infamous XXX-rated insider joke considered to be too filthy to perform in public.

ThinkFilm, which is distributing "The Aristocrats," says that AMC had agreed to show the film at theaters in Atlanta and Chicago, but then reneged. This comes despite an overwhelmingly good response from test audiences and critics alike.

Executive producer Penn Jillette says "Look, it's a stupid little movie that people are loving. So this is like a supermarket announcing that it's not going to carry vegetables. It's their right to do that. It's just a goofy decision based on one person's taste".

The film opens in limited release starting July 29th. To see the "South Park" version of the gag, click here and make sure no-one is in earshot.

Thanks to 'Jamie'.