As a guest on PBS genealogy program Finding Your Roots, Ben Affleck discovered one of his ancestors owned slaves and asked producers to suppress that fact, hacked Sony emails uploaded by WikiLeaks this week show.

The censorship—an apparent violation of PBS rules—is revealed in a July 2014 email thread between Sony Entertainment CEO Michael Lynton and Finding Your Roots host Henry Louis Gates Jr. In it, the two discuss the unusual request of an unnamed “megastar” later referred to as “Batman.”

“[C]onfidentially, 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 writes to Lynton. “We’ve never had anyone ever try to censor or edit what we found. He’s a megastar. What do we do?”

In his reply, Lynton recommends removing the material as long as “no one [else] knows,” before writing “all things being equal I would definitely take it out.”

Eventually, Gates acknowledges that fulfilling the request “would be a violation of PBS rules, actually, even for Batman” and “would embarrass him and compromise our integrity,” concluding, “Once we open the door to censorship, we lose control of the brand.”

Nonetheless, the episode aired without the information.

In a statement released by Gates on Friday, the Harvard professor denied removing the material at Affleck’s request, saying it was ignored so as to focus on “the most interesting aspects of his ancestry”:

We are very grateful to all of our guests for allowing us into their personal lives and have told hundreds of stories in this series including many about slave ancestors—never shying away from chapters of a family’s past that might be unpleasant. Ultimately, I maintain editorial control on all of my projects and, with my producers, decide what will make for the most compelling program.

In a parallel statement, PBS praised Gates’ “editorial integrity” and repeated his claim that “he and his producers made an independent editorial judgment to choose the most compelling narrative.”

On Thursday, WikiLeaks unveiled a searchable archive of the complete Sony hack, making it easier than ever to browse the company’s inconvenient executive emails.

[ Image via AP Images//h/t NY Daily News]