(CNN) A third woman has presented the Senate Judiciary Committee with allegations of inappropriate behavior by Supreme Court nominee Brett Kavanaugh, accusing him of sexually aggressive behavior at alcohol-fueled parties when he was in high school.

The new accuser, Julie Swetnick, was identified by her lawyer Michael Avenatti on Twitter Wednesday morning. In a sworn statement prepared by Avenatti and submitted to committee, Swetnick said that Kavanaugh and his friend Mark Judge were present at a party where she was drugged and "gang raped."

Swetnick did not identify Kavanaugh or Judge as her attacker in that incident. She said in her statement that there are two witnesses who can attest to her account, but she has not identified them publicly.

Kavanaugh's first public accuser, Christine Blasey Ford -- who will testify before the Senate Judiciary Committee on Thursday -- alleges that Kavanaugh and Judge, who both attended Georgetown Preparatory School, steered her into an upstairs bedroom at a high school party in 1982 where she says Kavanaugh put his hand over her mouth and attempted to take her clothes off on the bed before she escaped.

Kavanaugh, who will also testify on Thursday, has emphatically denied the allegations by Ford and a second woman who said he engaged in sexually inappropriate behavior with her at Yale. An attorney for Deborah Ramirez, the second accuser, said Tuesday on CNN that Republicans on the committee did not participate in a scheduled phone call earlier that day to discuss her allegations.

The White House issued an emphatic denial by Kavanaugh responding to Swetnick's allegation.

"This is ridiculous and from the Twilight Zone. I don't know who this is and this never happened," Kavanaugh said.

Judge's lawyer, Barbara Van Gelder, said in a statement, "Mr. Judge vehemently denies the allegations contained in the Swetnick affidavit."

In an interview with Fox News on Monday, the Supreme Court nominee said that he never sexually assaulted anyone and was a virgin through high school and for "many years after."

Swetnick, who attended Gaithersburg High School in Maryland, says she attended "well over ten" parties where Kavanaugh was present.

She says she witnessed Kavanaugh "drink excessively and engage in highly inappropriate conduct, including being overly aggressive with girls and not taking "No" for an answer. "This conduct included the fondling and grabbing girls without their consent," the sworn statement says.

In the sworn statement, she also alleges that Kavanaugh engaged "in abusive and physically aggressive behavior towards girls, including pressing girls against him without their consent, 'grinding' against girls and attempting to remove or shift girls' clothing to expose private body parts."

Swetnick says that in 1981 and 1982, she became aware of efforts by Judge, Kavanaugh and others to "spike the punch at house parties" so as to "cause girls to lose their inhibitions and their ability to say 'No.'"

She said at some parties boys lined up by a bedroom to assault incapacitated girls. Swetnick claims that the boys in the lineup included Kavanaugh and Judge, but does not say that they assaulted the girls, or the names of other witnesses who could corroborate it.

While Swetnick said she is aware of other witnesses who can attest to the truthfulness of her statements, she has not identified those witnesses.

She said she told at least two other people about the "gang rape" attack on her shortly after the incident, but she has not identified those people.

According to a committee aide, in an email to Avenatti on Wednesday, Republican committee staff said that "yesterday committee investigators interviewed Judge Kavanaugh again, under penalty of felony. Committee investigators specifically asked Judge Kavanaugh about all pending accusations, in specificity. This included your then-anonymous allegations and questions. He unequivocally denied all of the allegations, testifying that there was not a kernel of truth in any of these allegations. We have a transcribed interview. Judge Kavanaugh understood that he testified under penalty of felony, subject to up to 5 years of imprisonment. The Ranking Member's staff sat through the interview."

The Republican committee staff also said that they will do a follow-up interview with Kavanaugh Wednesday.

During an appearance on CNN's "The Lead with Jake Tapper" Wednesday afternoon, Avenatti said aides with the committee have said they would like to interview Swetnick.

Senate Judiciary Chairman Chuck Grassley tweeted Wednesday that he has 20 staff investigators looking into the allegations against Kavanaugh.

"We have had accusation after accusation and accusation. Very few of them if any are corroborated," he told reporters when asked about Swetnick's accusations earlier Wednesday. "Our lawyers, if we can make contact, get on it right away. Obviously with this one, we have a contact, and our lawyers are on it right now, our staff investigators."

Avenatti said committee staffers "refused to get back" to them after his initial contact with staff members, but he said Swetnick would be willing to testify before the Senate after the FBI conducted a full investigation.

"It was only within the last couple hours that they finally got back to us and said that they want to meet with my client," Avenatti said.

Trump calls new allegations 'ridiculous'

President Donald Trump initially declined to answer a question about the latest allegations against Kavanaugh as he departed the United Nations on Wednesday. Trump spoke briefly on North Korea and China, but kept walking out of the building when the Kavanaugh question was asked.

But the explosive allegations quickly prompted a fight between Trump and his longtime critic, Avenatti, whom he called "a third rate lawyer" and "a total low-life" on Twitter.

Avenatti responded in kind, calling Trump a "habitual liar and complete narcissist who also is a disgrace as a president and an embarrassment to our nation."

Speaking later Wednesday afternoon, Trump did not mention the new accuser by name in comments to the press, but he called the new allegations "ridiculous."

When a reporter asked Trump whether the three women who have accused Kavanaugh of sexual misconduct are lying, Trump curtly replied: "What's your next question?"

The President asserted that the new allegations are part of a Democratic "con game" to derail Kavanaugh's nomination.

"The Democrats are playing this game that's disgraceful," Trump said during an event with Japanese Prime Minister Shinzo Abe. "It's disgraceful to this country."

"If you look at this lawyer that came out he's a low-life," Trump said of Avenatti, who is considering a run for president as a Democrat in 2020. "He's a Democrat lawyer. Not a very good one."

Kavanaugh's attorney, Beth Wilkinson, said the Supreme Court nominee is outraged and mystified by the new allegations from Swetnick.

"He has never met this woman. He doesn't know Ms. Swetnick," Wilkinson said in an interview with CNN's Wolf Blitzer. "He didn't go to parties with her," she said, noting that she has spoken to other Kavanaugh high school friends and classmates.

"No one knows this woman. No one knows, remembers, seeing her at any of the parties that they attended," Wilkinson said. "Judge Kavanaugh doesn't know her. This never happened, and he's said that over and over and over again that he never engaged in any of that behavior."

Citing a concern that has been voiced by at least one senator, Wilkinson also questioned why anyone who had witnessed "gang rape" or boys drugging girls at parties would not have immediately reported that to police.

Wilkinson and South Carolina Sen. Lindsey Graham have questioned why Swetnick would have continued going to 10 parties where "gang rape" occurred, given that she and her friends would have been in danger.

"There's no excuse for her lawyer not going straight to the police. There's no one stopping any investigation, and any lawyer worth their salt would put their client's interest first and go straight to the police or the FBI," Wilkinson said.

Earlier this week after announcing that his client would be coming forward with new allegations against Kavanaugh, Avenatti said he had requested that the FBI investigate Swetnick's claims and he has not ruled out going to Maryland police to ask for an investigation.

Sixty men and women who attended Georgetown Prep or sister schools in Washington, DC, and said they knew Kavanaugh well during his time in high school signed a letter Wednesday to directly refute Swetnick, calling her allegations "nonsense."

"In the extensive amount of time we collectively spent with Brett, we do not recall having ever met someone named Julie Swetnick," the group said in the letter to the Senate Judiciary Committee. "Nor did we ever observe Brett engaging in any conduct resembling that described in Ms. Swetnick's declaration."

Avenatti has warned senators not to attack Swetnick's credibility, saying that his client passed multiple government security clearances over the course of her career, which included working at the Department of Justice, the US Mint, and the State Department.

"She is 100 percent credible and when the American people hear from her, they will determine, as I have, that she is to be believed," Avenatti said outside the federal courthouse in Los Angeles earlier this week where he participated in a hearing in the case involving one of his other clients, the adult film star Stormy Daniels, who says she had a sexual encounter with Trump and is suing the President for defamation. Trump has denied he had an affair with Daniels.

Avenatti said Swetnick would take a lie detector test, if Kavanaugh also agrees to take the test.

"This woman is showing incredible courage and bravery just like Dr. Ford," Avenatti said, referring to Kavanaugh's first accuser.

Wednesday was the first time that Trump has ever mentioned Avenatti by name, even though Avenatti has been one of the President's most vocal critics during the time that he has represented Daniels, whose real name is Stephanie Clifford.

Avenatti responded to Trump's insults in a series of tweets.

"Trump doesn't even know anything about my background," Avenatti said. "Knows nothing about my history of over $1 Billion in verdicts and settlements. I have represented Republicans and Democrats. I have represented hard working people throughout this nation."

Amidst the turmoil over his nominee, Trump said he is confident that Kavanaugh will be confirmed to the Supreme Court in the coming days.

"I think it's really working out very well," he said. "I think people are seeing what a disgrace these Democrat senators are."

This story is breaking and will be updated.