Rebel Wilson Alleges Sacha Baron Cohen Humiliated Her on Set in Graphic Account He Says Is 'Demonstrably False' (Exclusive)

Wilson writes in her new memoir that Baron Cohen asked her to commit a lewd act while making the 2016 comedy 'The Brothers Grimsby,' which he vehemently denies

In her new memoir, Rebel Rising, Rebel Wilson writes about her experience working with Sacha Baron Cohen — and headlines about her allegations regarding how he treated her on-set, adamantly denied by the Borat star, have already ignited controversy. Wilson writes she's "not about canceling anybody" but sharing her experience to help other women feel empowered to speak up.

She and Baron Cohen met at a dinner party in 2013, she writes in the memoir (excerpted in the new issue of PEOPLE), and he later called her, asking her to play his girlfriend in The Brothers Grimsby, a raunchy 2016 R-rated comedy he co-wrote, starred in and produced.

Once they began filming, Wilson, 44, writes, “It felt like every time I’d speak to SBC, he’d mention that he wanted me to go naked in a future scene. I was like, ‘Ha, I don’t do nudity, Sacha.’ ”

One day, while filming at a soccer stadium in Cape Town, she writes, “SBC summons me via a production assistant saying that I’m needed to film an additional scene. ‘Okay, well, we’re gonna film this extra scene,’ SBC says. Then he pulls his pants down ... SBC says very matter-of-factly: ‘Okay, now I want you to stick your finger up my ass.’ And I’m like, ‘What?? ... No!!’ ...”

Wilson continues in her book, “I was now scared. I wanted to get out of there, so I finally compromised: I slapped him on the ass and improvised a few lines as the character.”

Baron Cohen, 52, vehemently denies ever saying that, mistreating Wilson or pressuring her to go naked. His rep said in a statement: “While we appreciate the importance of speaking out, these demonstrably false claims are directly contradicted by extensive detailed evidence, including contemporaneous documents, film footage and eyewitness accounts from those present before, during and after the production of The Brothers Grimsby.”

Baron Cohen’s reps provided anonymous statements supporting the comedian from nine people they say were involved in the film. Five said they witnessed the Cape Town scene, and all dispute Wilson’s account.

Related: Rebel Wilson Calls Sacha Baron Cohen 'A--hole' Named in Her Book, Says She 'Will Not Be Bullied or Silenced'

“As per the script, which Rebel had read and approved in advance, her character was attempting to put a finger in Sacha’s character’s butt. At no point did Sacha actually ask her to put a finger in his butt,” said a producer. “Throughout this entire period, she was treated with the utmost respect and empowerment and was welcomed as a collaborator in all creative areas.”

Added a writer-producer: “This was a scheduled, scripted scene."

Wilson’s sister Liberty and a friend told PEOPLE that Wilson spoke to them soon after the incident in Cape Town and recounted what she says happened.

Wilson writes that she called her agent and spoke to a lawyer. “I was encouraged to ‘be professional and finish the film,’ ” she writes. After that, “my way of dealing with it at that point was to try to laugh it off.”

Then, Wilson writes, she was asked to do reshoots, including a sex scene. “I filmed the scene, after demanding rewrites. But I still had to simulate having sex with this guy. I still had to kiss him repeatedly.” A few months later, she continues, “It really sank in that all this wasn’t something that could be laughed off. I relayed to the producers that I would not be doing any promotion for the film.”

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In the end, Wilson writes, "The movie bombed, which to me was karma enough. I’m not about canceling anybody and that’s not my motivation for sharing this story. I’m sharing my story now because the more women talk about things like this, hopefully the less it happens.”

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