The move, no doubt intended to insulate him from any potential public fallout stemming from the revelation, has backfired badly, with the revelation that he not only made the request, but that the producers complied.

Details of the request were found among a tranche of hacked emails from the film and television studio Sony Pictures, which have been made public by Wikileaks.

Affleck was profiled by the genealogy show Finding Your Roots, which unearths the extended family tree of high-profile subjects.

But when Finding Your Roots did exactly as the show's title suggests, Affleck, who is to star in the upcoming Batman v Superman, asked them to ignore one particular ancestor, who was a slave owner.

The show's host, Henry Louis Gates Jr, contacted his friend, US Sony CEO Michael Lynton, for advice.

"For the first time, one of our guests has asked us to edit out something about one of his ancestors – the fact that he owned slaves," Gates asked.

"We've never had anyone ever try to censor or edit what we found. He's a megastar. What do we do?"

Gates also noted that "four or five" of the show's recent subjects also descended from slave owners, implying it was not such an unusual discovery.

He also admitted concealing information would be a violation of the programs remit from the US public broadcaster PBS, which airs it. "Even for Batman," Gates added.

Lynton advised taking out the contentious material, but warned of the risks if it was discovered.

"I would take it out if no one knows, but if it gets out that you are editing the material based on this kind of sensitivity then it gets tricky," Lynton said. "All things being equal I would definitely take it out."

Gates replied: "It would embarrass him and compromise our integrity."

Gates is an acclaimed documentary producer with a long list of credits and a professor based at the prestigious Harvard University,

The program in which Affleck was profiled aired in October 2014.

When broadcast, it made no mention of the fact that the actor had an ancestor who owned slaves, instead focusing on an ancestor from the Revolutionary War, another who was an occult enthusiast and his mother, who marched for civil rights in 1964.

A statement from PBS defending the decision said it was an "independent editorial judgement", though that is difficult to reconcile with Gates own admission that it stemmed from a request by Affleck.

Gates also issued a statement, defending the decision on the basis that on other programs they have included details about slave owning ancestors, "never shying away from chapters of a family's past that might be unpleasant".

"In the case of Mr Affleck, we focused on what we felt were the most interesting aspects of his ancestry," Gates said.

Affleck has not commented.