Jerry Lewis said film footage that would never see the light of day has appeared on YouTube.
Lewis Never marketed his movie The Day The Clown Cried after it was completed in 1972. He told journalists in Cannes: "I thought the work was bad. I lost the magic."
The film told the story of a clown who used to entertain children in a Nazi death camp during WWII.
The YouTube video shows Lewis in costume and giving directions to the cast and crew.
The production had numerous problems including a shortage of money. Lewis ended up paying costs out of his own pocket to finish the film.
Speaking at the Cannes Film Festival in May, he told reporters, "No one will ever see it, because I'm embarrassed. Lewis was in Cannes to promote the first film he had made in 20 years.
He added, "I believed in the work and the way it should have been, and it wasn't."
Lewis played a failed clown name Helmut Doork in the film. Doork, after being locked up in a Nazi camp for drunkenly mocking Adolf Hitler, is used by officers to entertain Jewish children on their way to Auschwitz.
Jerry Lewis wrote the movie, called The Day The Clown Cried, based on a script by Joan O'Brien and Charles Denton.
Harry Shearer saw a private screening in 1979 and said: "This movie is so drastically wrong, its pathos and its comedy are so wildly misplaced, that you could not, in your fantasy of what it might be like, improve on what it really is."
The video of The Day The Clown Cried apparently was first aired on a Flemish website last year.