American History X is a 1998 drama film directed by Tony Kaye. It stars Edward Norton as a Nazi skinhead that makes a remarkable transformation after 3 years in prison. It received critical acclaim for its realistic portrayal of it's subject matter, and it earned Norton an Academy Award nomination for Leading Actor.
The surviving film was actually stolen from the director's hands by both New Line Cinema (the film's distributor) and Edward Norton (who is a notoriously difficult actor to deal with). Several squabbles over what scenes should stay and what order they should be in, resulted in an extremely lengthy post-production process. After New Line Cinema rejected Kaye's edited cut, Norton eventually ended up helming the editing process, allegedly tailoring his cut in order to specifically give himself more screentime, something Kaye believes "ruined" the film. There is little information available towards what exactly was different.
It is widely believed that Norton destroyed many of the master copies of the deleted scenes. Only a handful of scenes were featured on the movie's DVD or leaked onto the internet. Kaye did eventually release a documentary about the struggles the film's production had, but even that movie has been screened a limited amount of times. To this day, it is unknown exactly how many more scenes have yet to be released, if any.
Update June 1st, 2014: Dycaite recently had a full workprint of the fabled Director's Cut sent to him, of which he mirrored on Mega Upload . The print, while not terribly different from the final product, does feature many different camera angles and less screentime from Edward Norton. This has shed a lot of light on this legendary film, however, it is not confirmed if the workprint sent to Dycaite is the full director's cut. Until confirmation can be given, a search does continue regardless. Thank you goes to the uncredited anonymous source.