Matt Lauer 'Believes He Is Innocent' and 'Feels Angry' About Rape Allegation, Source Says

Matt Lauer, who has denied raping his former NBC News colleague Brooke Nevils, feels that the allegation is “unfair,” a source close to him tells PEOPLE.

“Matt believes that he is innocent of this charge and feels angry over the accusation,” the source says. “He said he did have a very casual consensual relationship with her but no violence of any kind, and he intends to defend himself. He feels like this in unfair, sour grapes on her part.”

A rep for Lauer did not immediately respond to PEOPLE’s request for comment.

Her allegation was made public Tuesday night when Variety published details from Ronan Farrow‘s upcoming book, Catch and Kill: Lies, Spies, and a Conspiracy to Protect Predators — in which Nevils alleges that Lauer anally raped her in his hotel room at the 2014 Sochi Olympics. Nevils reportedly told Farrow she was “too drunk to consent” and also stated multiple times that she did not want to have anal intercourse.

Nevils said in the book that she had more sexual encounters with Lauer back in New York City, according to Variety, telling Farrow: “It was completely transactional. It was not a relationship.”

Lauer, 61, penned a lengthy letter to Variety responding to the allegations Wednesday. The ousted Today co-anchor wrote that the encounter in Sochi was the beginning of his affair with Nevils and called it “extramarital, but consensual.”

RELATED: Matt Lauer’s Ex-Wife Annette Roque Breaks Her Silence on Rape Allegation

“At no time, during or after her multiple visits to my apartment, did she express in words or actions any discomfort with being there, or with our affair,” he said. “She also went out of her way to see me several times in my dressing room at work, and on one of those occasions, we had a sexual encounter. It showed terrible judgment on my part, but it was completely mutual and consensual.”

Lauer, who pointed out what he claims are “contradictions” in Nevils’ story and acknowledged that people were aware of the affair, concluded by stating that he has “never assaulted anyone or forced anyone to have sex. Period.”

Matt Lauer | Charles Sykes/Invision/AP/REX/Shutterstock
Matt Lauer | Charles Sykes/Invision/AP/REX/Shutterstock

Nevils slammed Lauer’s open letter later Wednesday, calling it a “case study in victim shaming.”

“There’s the Matt Lauer that millions of Americans watched on TV every morning for two decades, and there is the Matt Lauer who this morning attempted to bully a former colleague into silence,” Nevils said on a statement that aired on NBC Nightly News.

“I am not afraid of him now,” Nevils said. “Regardless of his threats, bullying, and the shaming and predatory tactics I knew he would (and now has) tried to use against me.”

RELATED: Matt Lauer Is ‘Hunkered Down in the Hamptons’ as NBC Colleague Accuses Him of Rape, Source Says

NBC News Chairman Andrew “Andy” Lack has expressed support of Nevils and claimed that the television broadcasting company did not know of Lauer’s alleged conduct before he was fired in 2017.

“First, and most importantly, in reading today’s news our hearts go out to our former colleague. Matt Lauer’s conduct in 2014 was appalling and reprehensible — and of course we said so at the time,” Lack wrote in an internal memo to NBC staff obtained by PEOPLE.

“The first moment we learned of it was the night of November 27, 2017, and he was fired in 24 hours. Any suggestion that we knew prior to that evening or tried to cover up any aspect of Lauer’s conduct is absolutely false and offensive,” Lack added.

Since the incident, Lack said that NBC has worked to “improve our culture and ensure we have a workplace where everyone feels safe and respected, as well as protected in raising claims.”

“We’ve required all NBC News employees to complete in-person workplace behavior trainings and we’ve significantly increased awareness of the ways employees report concerns – anonymously or otherwise,” Lack added.

If you or someone you know has been sexually assaulted, please contact the National Sexual Assault Hotline at 1-800-656-HOPE (4673) or go to online.rainn.org.