In 1972, the great comedian Jerry Lewis set out to direct and star in a film called The Day the Clown Cried. The World War II set film told the story of a washed-up circus clown who was sent to a Nazi prison (and eventually concentration) camp. The 'finished' feature has never been released.

The reasons for its disappearance are many. The shoot was best by numerous problems, both financial and practical. Due to various complications, it never reached screens. 87-year old Lewis has repeatedly said he is relieved he has the power to suppress it and vows the public will never see it.

Indeed, legend has it that it that the cut that allegedly exists is fascinating and wildly insensitive in equal measure. Actor Harry Shearer claims to have seen it, and told Spy Magazine in 1992 that "seeing this film was really awe-inspiring, in that you are rarely in the presence of a perfect object. This was a perfect object. 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."

It's unlikely we'll ever see the complete The Day the Clown Cried. Perhaps we wouldn't want to. However, in a gift to curious film fans, a brief Flemish making of documentary has surfaced and been uploaded to YouTube, including some footage from the film. It's one of the few insights we're likely to get into one of the most infamous unreleased films of all time: