Supreme Court nominee Brett Kavanaugh became aggressive and belligerent when he drank during his first year at Yale University, according to his freshman roommate.

James Roche, who shared a two-bedroom unit with Kavanaugh on campus, said Monday while the pair did not socialize together, they spoke in their home, and Roche would see Kavanaugh return from nights out with his friends.

"It is from this experience that I concluded that although Brett was normally reserved, he was notably a heavy drinker, even by the standards of the time, and that he became aggressive and belligerent when he was very drunk," Roche, now a software company CEO based in San Francisco, told one of ABC's California affiliates before circulating a statement on Twitter.

[Related: Kavanaugh classmates rescind names from statement rejecting second accuser’s allegation]

Deborah Ramirez, a fellow Yale alum and close friend of Roche's, is accusing Kavanaugh of thrusting his penis in her face at a college party during the 1983-84 academic school year when he was a freshman. The judge has categorized the allegation, first reported by the New Yorker at the weekend, as a "smear, plain and simple."

Roche, who does not describe himself as political, reiterated Monday that he found Ramirez's story to be credible, even though he said he did not witness the interaction firsthand.

"I did not observe the specific incident in question, but I do remember Brett frequently drinking excessively and becoming incoherently drunk," he said.

"Based on my time with Debbie, I believe her to be unusually honest and straightforward, and I cannot imagine her making this up," Roche added. "Based on my time with Brett, I believe that he and his social circle were capable of the actions that Debbie described."

Kavanaugh told Fox News later Monday he had never consumed so much alcohol that he blacked out and failed to remember what happened while he had been drinking. He made the comments after admitting he consumed alcohol in high school, although he was underage.

Kavanaugh is due to appear before the Senate Judiciary Committee on Thursday to address a claim made by another woman, Christine Blasey Ford, that he drunkenly forced himself on her at a Maryland high school party in 1982. He has also denied Ford's accusation.