The BBC has released a short documentary about Jewish comedian Jerry Lewis’ never-before-seen Holocaust film.

“The Day the Clown Cried,” which Lewis wrote and directed at the height of his Hollywood career in 1971, has never been released. The BBC documentary released on Tuesday includes behind-the-scenes footage of production, stills from the film and narration by Jewish comedian David Schneider.

The film was reportedly a drama with comedic elements. It centers on a fictional clown named Helmut Doork who is imprisoned by the Nazis and is forced to lead children into the gas chambers.

“This is a very interesting film because very few people have seen anything from it, Swedish film critic Jan Lumholdt told the BBC. “He’s a comedian and this is his most serious film ever. This gives it a very interesting energy and dynamic.”

Jerry Lewis (International Film Circuit, Inc.)

Jerry Lewis (International Film Circuit, Inc.)

Lewis was reportedly passionate about the project at first but has hidden all of its footage, saying recently that he is too embarrassed to show it.

“It was all bad, and it was bad because I lost the magic,” Lewis told Reuters in 2013. “You will never see it. No one will ever see it, because I am embarrassed at the poor work.”