It’s probably the most famous movie that no one has ever seen.

In 1972 Jerry Lewis, then at the zenith of his international popularity as a comedian and director, adapted a decade-old script, directing and starring in “The Day The Clown Cried,” the fictional story of a Jewish clown in a Nazi concentration camp. Most of the filming took place in Sweden.

Two decades before Roberto Benigni’s Oscar-winning “Life is Beautiful,” about a father and son in a concentration camp, set the tone for a number of so-called Holocaust comedies, Lewis’ film broke new ground.

But Lewis never completed the production, never released it, and never fully explained why.

Since then, “The Day The Clown Cried” has achieved an iconic place among students of the Shoah and cinema, becoming, according to a new documentary, one of the most sought-after films in the world.

Last week a unit of the British Broadcasting Corporation released a documentary on the film. Produced by BBC South, “The Story Of The Day The Clown Cried” is available now only online (bbc.co.uk/programmes/p03dj9kr), featuring rare footage from the production, interviews with cast members and speculation about Lewis’ reasons for deciding that the film should not be seen.

The documentary may be carried on one of BBC’s many channels “one of these days,” said producer Richard Latto. “We’re very hopeful.”

Latto, a veteran BBC producer who “is not from a Jewish background,” heard about the film 15 years ago, while in college, and became fascinated by it as an example of “comedy that pushes the envelope.”

A Holocaust comedy by Lewis, then best known for “The Nutty Professor,” a comedian who would make “funny noises for comic effect,” was an image changer, Latto told The Jewish Week in a telephone interview. “You would never imagine him tackling a topic like the Holocaust.”

Busy with other projects, Latto picked up his research in the Lewis film five years ago, enlisting Jewish comedian David Schneider, whose mother was a refugee from Nazi Austria, to serve as narrator and on-screen interviewer.

Latto reached out to Lewis to take part in the production; Lewis did not reply.

The documentary includes excerpts from a television interview in which Lewis said he was “embarrassed” by the way “The Day The Clown Cried” turned out. “I was ashamed of the work … it was bad, bad, bad.”

The BBC documentary also alludes to a financial reason for scrapping the film’s release — Lewis did not receive sufficient support from backers.

Lewis, 89, last year donated a collection of his films to the Library of Congress, reportedly including “The Day The Clown Cried” — but it is not clear if it is a complete copy or a partial one, featuring some scenes filmed in France.

According to a provision of Lewis’ donation, the LOC copy of the 1972 production cannot be shown in public until 2025. “I would be surprised,” Latto said, “if we see it in his lifetime.”

steve@jewishweek.org