Robert De Niro says he welcomes disagreement about whether The Irishman is accurate, but wasn’t “conned” into believing the firsthand accounts of Frank “The Irishman” Sheeran, the mob enforcer he plays in the film.

Sheeran told what he said was his true life story in I Heard You Paint Houses, by Charles Brandt. The book is the basis for The Irishman. Brandt said that six weeks before Sheeran died in 2003, at the age of 83, he held up a copy of I Heard You Paint Houses and stood by everything that appears in the book.

That includes Sheeran’s explanation of what happened to labor leader Jimmy Hoffa, who is played by Al Pacino in the film. Hoffa disappeared in 1975, and what happened to him is one of the great unsolved crimes in American history.

A recent Daily Beast story said that Dan Moldea, author of the book The Hoffa Wars, confronted De Niro in 2014, when The Irishman was in development, to warn him that Sheeran, a convict with a drinking problem, wasn’t reliable.

Also Read: What You Need to Know Before Seeing Martin Scorsese’s Take on the Jimmy Hoffa Story

“I told him, ‘Bob, you’re being conned,’” Moldea recalled.

In an interview with IndieWire, De Niro said that isn’t the case.

“Dan is a well-respected writer. I met him in D.C. for a writers thing where they get together every year. He said that we’re getting conned. I wasn’t getting conned,” De Niro said. “I have no problem with people disagreeing. He of course is an authority on Hoffa and everything else. As Marty says, ‘We’re not saying we’re telling the actual story. We’re telling our story. I believed it.’

In a recent Directors Guild of America interview with Spike Lee, Scorsese made it clear that he isn’t deeply concerned with whether Sheeran’s account of what happened to Jimmy Hoffa is true.

“When I took on the picture, I made it very clear… I’m not interested,” Scorsese said. “We know he’s gone. How did he go, meaning what brought him to that point, is more interesting to me. And it’s really about the closeness, the friendship, the trust, and all that sort of thing.”

Brandt did not respond to a request for comment.

I Heard You Paint Houses and The Irishman provide an account, largely from Sheeran’s point of view, of how he befriended and ultimately betrayed Hoffa, a labor leader who Sheeran says was once as famous as Elvis Presley or The Beatles.

But his account has been disputed by some Hoffa insiders.

Harvard Law School professor Jack L. Goldsmith, the stepson of Charles “Chuckie” O’Brien (played by Jesse Plemons in The Irishman) told Vanity Fair that “there’s absolutely no basis for Sheeran’s claim and a lot of reasons to think it’s preposterous.” His new book, In Hoffa’s Shadow, offers a different account of the Jimmy Hoffa story than you’ll get from I Heard You Paint Houses or The Irishman.

Author and investigative reporter Vince Wade, meanwhile, recently wrote for The Daily Beast that I Heard You Paint Houses stories get several details provably wrong, including that Salvatore “Sally Bugs” Briguglio had “thick, curly black hair”—Wade says it was sandy brown and not curly— and that the Machus Red Fox restaurant, a key locale in Hoffa’s disappearance, was not “set back quite a way in the parking lot” as Sheeran asserts in I Heard You Paint Houses.

Robert De Niro is a producer as well as the titular character in The Irishman, and Brandt says in an update to I Heard You Paint Houses that he met with De Niro, Scorsese and The Irishman screenwriter Steven Zaillian to tell them a couple of Frank Sheeran stories that never made it into the book.

The Irishman is in theaters now in New York and Los Angeles and premieres on Netflix on Nov. 27.