A third woman has come forward with sexual misconduct allegations against Supreme Court nominee Brett Kavanaugh, saying that she witnessed Kavanaugh, in high school, behaving overly aggressive toward women, spiking their drinks and fondling them without consent. She further alleged that she was a victim of a "gang rape" that he witnessed.

The allegations were made public in a tweet by lawyer Michael Avenatti, who has gained fame for his representation of porn star Stormy Daniels in her lawsuit against President Trump and is representing the accuser.

According to a sworn affidavit tweeted by Avenatti on Wednesday, a woman named Julie Swetnick is alleging that she witnessed Kavanaugh and his friend Mark Judge attend “well over ten house parties” in the Washington, D.C. area between 1981 and 1983 — when the two were in high school.

Swetnick, 55, reached out to Avenatti first for representation.

“On numerous occasions at these parties, I witnessed Mark Judge and Brett Kavanaugh drink excessively and engage in highly inappropriate conduct, including being overly aggressive with girls and not taking ‘No’ for an answer,” writes Swetnick. “This conduct included the fondling and grabbing of girls without their consent.”

The woman, Swetnick, is a graduate of Gaithersburg High School in Maryland, sand says she holds active government clearances with the Department of Treasury, Internal Revenue Service and U.S. Mint. Swetnick says she has also held numerous other security clearances in various federal government jobs in Washington, including at the Justice Department and State Department.

The revelation of Swetnick’s story comes as Kavanaugh faces sexual assault allegations from two other women, Christine Blasey Ford and Deborah Ramirez. Kavanaugh and Ford are set to testify before the Senate Judiciary Committee on Thursday.

Swetnick also alleges she observed Kavanaugh “drink excessively” at these parties, and “engage in abusive and physically aggressive behavior towards girls.”

“I often witnessed Brett Kavanaugh speaking a demeaning manner about girls in general as well as specific girls by name,” Swetick alleges in her declaration. “I also witnessed Brett Kavanaugh behave as a ‘mean drunk’ on many occasions at these parties.”

Swetnick also describes that Kavanaugh, Judge and other boys put grain alcohol and/or drugs in the drinks at house parties to "cause girls to lose inhibitions and their ability to say 'No.' "

Kavanaugh, Judge and other guys tried to cause girls to become "inebriated or disoriented" so they "could then be 'gang raped' in a side room or bedroom by a 'train' of numerous boys."

"I have a firm recollection of seeing boys lined up outside rooms at many of these parties waiting for their 'turn' with a girl inside the room. These boys included Mark Judge Brett Kavanaugh," Swetnick said.

Swetnick also said that "in approximately 1982 I became the victim of one of these 'gang' or 'train' rapes where Mark Judge and Brett Kavanaugh were present."

She claims to have told two other people, whom she did not name, after the incident.

Swetick says other women told her that Kavanaugh also acted this way during “summer months” in Ocean City, Md.

There are other witnesses that can attest to her allegations, she says.

Swetnick says the sworn affidavit is given under “penalty of perjury” and it is all true and correct.

As part of his tweet, Avenatti also included correspondence he has had with Mike Davis, the top lawyer for the Senate Judiciary Committee, about Swetnick's allegations.

"Below is my correspondence to Mr. Davis of moments ago, together with a sworn declaration from my client. We demand an immediate FBI investigation into the allegations. Under no circumstances should Brett Kavanaugh be confirmed absent a full and complete investigation," wrote Avenatti.

Avenatti has sent Swetnick's affidavit to the Senate Judiciary Committee. A spokesperson for Grassley’s office said Avenatti provided a copy to the committee Wednesday morning, and that committee lawyers “are in the process of reviewing it now.”

Before posting the allegations, on Tuesday, Avenatti addressed and denied rumors that he had been duped by someone posing as a woman making a third allegation against Kavanaugh. "This is completely false," Avenatti said Tuesday on Twitter. "It never happened; it is a total fabrication. None of it is true. The right must be very worried. They should be."

Ramirez came forward late Sunday to publicly accuse the judge of exposing himself to her during a Yale University party in the 1980s when they were undergraduates at the school.

Ford, the first woman to come forward, alleges Kavanaugh drunkenly forced himself on her in 1982, when he would have been 17, at a Maryland high school house party.

Kavanaugh has repeatedly denied committing any sexual misconduct, and also claimed in an interview Monday that he was a virgin in high school and "for many years thereafter."

President Trump and the White House have steadfastly supported Kavanaugh.

Senate Judiciary Committee Chairman Chuck Grassley has scheduled a possible vote for Kavanaugh on Friday.