Martin Scorsese's new film is based on a book by Charles Brandt, but many have long claimed details in the novel are not true.

Martin Scorsese’s “The Irishman” tells the alleged true story of Frank Sheeran, a war veteran who becomes a hitman for the mob and plays a key role in the disappearance of Teamster leader Jimmy Hoffa. “Irishman” screenwriter Steven Zaillian wrote the script based on Charles Brandt’s novel “I Heard You Paint Houses,” in which the author interviewed the real-life Sheeran about his time in the mob. Sheeran claims he killed Jimmy Hoffa by shooting him twice in the back of his head while in a house in northwest Detroit. Sheeran’s admission is refuted by investigative reporters on the Hoffa case and FBI members in a new report from The Daily Beast, published on the same day “The Irishman” opened in select theaters from Netflix.

In The Daily Beast report, writer Vince Wade spoke with investigative reporter Dan Moldea, who has been working on the Hoffa case for years and published a book on the union leader titled “The Hoffa Wars.” In real life, Hoffa’s body was never discovered and his blood wasn’t found in the house where he was allegedly killed, which has only added to the mystery around Sheeran’s claim.

Moldea tells The Daily Beast that he confronted Robert De Niro face to face in 2014 and warned him not to make “The Irishman” because it was based on an untrue story. De Niro stars as Frank Sheeran in the movie and worked over a decade to develop the project after first reading Randolph’s book in 2004.

“De Niro couldn’t have been nicer,” Moldea told The Daly Beast. “Terrific guy. But I was very aggressive. I knew I had a finite period of time with this guy. I had to get to the point. I told him, ‘Bob, you’re being conned.’ I told him in no uncertain terms, ‘Bob, you are being conned.’”

Moldea says De Niro took offense at his warning and the conversation got aggressive. “I talked to him the way he talks to people in the movies,” Moldea added. IndieWire has reached out to De Niro’s representative for further comment. The Daily Beast reports that Moldea has a photo of himself with De Niro at a December 2014 dinner in Washington D.C. where the encounter occurred.

“The Irishman” is now playing in select theaters. The movie will hit Netflix’s streaming platform beginning November 27. Head over to The Daily Beast’s website to read more about the case behind the film’s alleged true story.

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