A classmate of Supreme Court nominee Brett Kavanaugh has accused him of lying under oath about his "heavy" drinking.
Charles Ludington said that he was "deeply troubled" by the judge's "blatant mischaracterisation".
Mr Kavanaugh is accused of sexual assault by several women, which are being investigated by the FBI.
He rejects the charges as well as ever drinking to the point of memory loss. President Donald Trump denies limiting the FBI inquiry into the judge.
The new inquiry has delayed a final vote on Judge Kavanaugh, who if confirmed is likely to tip America's highest court in favour of conservatives.
Rachel Mitchell, the Arizona prosecutor hired by Republicans to question Professor Christine Blasey Ford during the hearings last week, gave her memo to senators on Sunday.
In it, she questioned Prof Ford's credibility, calling her case weak and saying she did not think "that a reasonable prosecutor would bring this case based on the evidence before the Committee".
What did the classmate say about Mr Kavanaugh?
Prof Ludington, who teaches at North Carolina State University, said he had seen Judge Kavanaugh slurring his words and staggering after excessive alcohol consumption while at Yale.
The professor also said Judge Kavanaugh "was often belligerent and aggressive" when drunk.
"I can unequivocally say that in denying the possibility that he ever blacked out from drinking, and in downplaying the degree and frequency of his drinking, Brett has not told the truth."
He noted that it was not Judge Kavanaugh's drinking habits in college that worried him - it was the fact that he made questionable statements under oath.
"If he lied about his past actions on national television, and more especially while speaking under oath in front of the United States Senate, I believe those lies should have consequences," Prof Ludington said.
The professor plans to speak with the FBI on Monday, according the New York Times.
His statement contradicts another Yale classmate - former NBA player Chris Dudley - who told The Washington Post he "never, ever saw Brett Kavanaugh black out" from alcohol consumption.
When asked about Judge Kavanaugh's drinking habits during a news conference on Monday, Mr Trump said he thought his answers during the hearing were "excellent".
"He had a little bit of difficulty, he talked about things that happened when he drank," Mr Trump said. "This is not a man who said that he was perfect with respect to alcohol."
What is the FBI investigating?
Prof Ludington and Mr Dudley are among several of Judge Kavanaugh's classmates who have recently spoken out about his behaviour at Yale.
The discussion around the top court nominee's drinking habits forms part of the FBI inquiry, which is expected to be completed within a week.
US media report that the FBI spoke with Ms Ramirez, who accuses Judge Kavanaugh of exposing his genitals to her during a college party, on Sunday.
Opposition Democrats have accused the administration of trying to limit the scope of the inquiry, amid media reports that Judge Kavanaugh's third accuser - Julie Swetnick - would not be interviewed.
Mr Trump has denied imposing any restrictions, saying he wanted the FBI "to interview whoever they deem appropriate".
Wow! Just starting to hear the Democrats, who are only thinking Obstruct and Delay, are starting to put out the word that the “time” and “scope” of FBI looking into Judge Kavanaugh and witnesses is not enough. Hello! For them, it will never be enough - stay tuned and watch!— Donald J. Trump (@realDonaldTrump) September 30, 2018
Despite this, NBC news quoted a White House official as saying restrictions remained in place, adding that as the FBI is carrying out a background - not a criminal - investigation, the White House decides the parameters of the probe.
The most senior Democrat on the Senate's Judiciary Committee, Dianne Feinstein, has sent a letter urging the White House to release the written directive sent by President Trump to the FBI launching the investigation.
Although the Senate Judiciary Committee on Friday approved Judge Kavanaugh's nomination, it was conditional on a new inquiry into what it said were the "credible allegations" facing him.
As the investigation is not a criminal one, the FBI will not say whether it believes the allegations are true.
Who are Mr Kavanaugh's accusers?
The first woman to come forward with allegations against Mr Kavanaugh was psychology professor Christine Blasey Ford. She testified at a hearing last week that he tried to remove her clothing, pinned her to a bed and covered her mouth at a house party in 1982, when she was 15 and he was 17.
In response to her testimony, Judge Kavanaugh said he had never assaulted her or anyone else. He accused Democrats of politicising the process and harming his family and good name.
Two other women have also come forward: Ms Ramirez, who attended Yale at the same time as Mr Kavanaugh, says he exposed his genitals to her during a college drinking game.
Ms Swetnick says she went to house parties attended by Mr Kavanaugh in the early 1980s, where she said he and his friends had tried to "spike" girls' drinks. He has denied both accusations.
Kavanaugh's roommate at Yale remembers Brett 'drinking excessively'
RNZ obtained a statement from James Roche who said he will not be granting any more interviews or answering any more questions at this time.
The statement reads:
"I was Brett Kavanaugh's roommate at Yale University in the Fall of 1983. We shared a two-bedroom unit in the basement of Lawrence Hall on the Old Campus. Despite our living conditions, Brett and I did not socialize beyond the first few days of freshman year. We talked at night as freshman roommates do and I would see him as he returned from nights out with his friends. It is from this experience that I concluded that although Brett was normally reserved, he was a notably heavy drinker, even by the standards of the time, and that he became aggressive and belligerent when he was very drunk. I did not observe the specific incident in question, but I do remember Brett frequently drinking excessively and becoming incoherently drunk.
"I became close friends with Debbie Ramirez shortly after we both arrived at Yale. She stood out as being exceptionally honest, with a trusting manner. As we got to know one another, I discovered that Debbie was very worried about fitting in. She felt that everyone at Yale was very rich, very smart and very sophisticated and that as a Puerto Rican woman from a less privileged background she was an outsider. Her response was to try hard to make friends and get along.
"Based on my time with Debbie, I believe her to be unusually honest and straightforward and I cannot imagine her making this up.
"Based on my time with Brett, I believe that he and his social circle were capable of the actions that Debbie described.
"I do not consider myself to be a political person and I have no political agenda. I have shared this information with a small number of reporters who reached out to me directly because Debbie has a right to be heard and I believe her."
- BBC / RNZ