Attorney Alan Dershowitz, the Harvard professor and lawyer for convicted sex offender Jeffrey Epstein, is the subject of a new defamation lawsuit from one of Epstein’s accusers.

In the suit, Virginia L. Giuffre, previously known as Virginia Roberts, said that she was a victim of sex trafficking and abuse by billionaire Jeffrey Epstein over a decade ago and that Dershowitz falsely claimed she had fabricated the accusations.

The suit alleges that Dershowitz "was also a participant in sex trafficking, including as one of the men to whom Epstein lent out Plaintiff for sex."

Dershowitz has adamantly denied the allegations.

Giuffre says in the in the suit filed Tuesday that she was the victim of sex trafficking and abuse by Epstein during 2000 to 2002, beginning when she was 16 years old.

"When Epstein was arrested for sex trafficking in 2006, Dershowitz defended his friend and client by falsely attacking the veracity of his accusers, including calling the children whom Epstein had abused [and, in the case of Plaintiff, the Defendant himself had also abused], liars and prostitutes,” the defamation suit filed by Giuffre says.

The lawsuit was first reported by the Miami Herald Tuesday.

Dershowitz said in phone interview with NBC News on Tuesday that he welcomed the lawsuit and will prove that Giuffre is lying.

"I welcome this lawsuit. I've been looking for an opportunity to prove in court that this woman made up whole story," Dershowitz said. "I will prove that she committed perjury. I never met her."

In an exhibit filed in connection with the defamation case, another woman, Maria Farmer, claimed in a sworn affidavit that she worked for Epstein in 1996 to purchase art, but her duties also included manning the front door at his New York mansion and keeping records of visitors.

She said in the exhibit that she saw a number of schoolage girls coming to the home and that they would be escorted upstairs, and that Dershowitz came to visit Epstein "a number of times."

She also said in the exhibit that: “On a number [of] occasions I witnessed Dershowitz at the NY mansion going upstairs at the same time there were young girls under the age of 18 who were present upstairs in the house.”

Dershowitz told NBC News that "I can prove that Maria Farmer never met me," and that “I never met Jeffrey Epstein until after she stopped working for him."

"She could have never have seen me," Dershowitz said.

Joshua Schiller, Giuffre’s attorney in the defamation suit, said the complaint contains detailed allegations. "We look forward to proving these allegations in a court of law," he said.

Giuffre’s attorney in Florida, Sigrid McCawley, said that "Ms. Guiffre's complaint is supported by detailed factual allegations, contemporaneous documents and sworn affidavits."

"Mr. Dershowitz's response in court will have to be more than the conclusory denials and ad hominem attacks on victims and their lawyers that continue to be the core of his desperate media strategy," she said.

Epstein pleaded guilty to state charges of soliciting prostitution in 2008.

Epstein, 66, served 13 months in jail and was allowed to leave jail regularly through a work release program.

Jeffrey Epstein in 2005. Sipa via AP file

Senate Democrats last week demanded that the Department of Justice disclose the full results of its investigation into whether U.S. Labor Secretary Alexander Acosta is guilty of “professional misconduct” in his handling of the sex crimes prosecution against Epstein. The agency opened an investigation in February.

Acosta was the U.S. attorney for South Florida in 2007 when federal prosecutors struck a deal that allowed Epstein to plead guilty in state court and ruling out federal charges.

The suit filed Tuesday by Giuffre alleges that Dershowitz made “knowingly false and malicious defamatory statements” on behalf of himself and Epstein.

Those allegedly false statements included claims by Dershowitz that "the story was 100 percent flatly categorically made up" and that "Roberts and her attorneys fabricated the assertion in order to get money from other powerful, wealthy people."

According to a civil lawsuit filed by other women who claim that they were among Epstein's victims, one of the conditions of the deal reached with prosecutors was that a much larger federal investigation into Epstein and others allegedly involved in enabling in his scheme would be dropped.

An investigation by The Miami Herald said that Acosta helped engineer the deal involving only state charges and agreed that it would be kept secret from other victims until it was presented in court, denying them a chance to object.

Giuffre’s defamation suit seeks a judgment against Dershowitz “awarding compensatory, consequential, exemplary, and punitive damages in an amount to be determined at trial, but in excess of the $75,000 jurisdictional requirement,” as well as any attorney’s fees.

Acosta has said previously that the case against Epstein became stronger after the state conviction because more victims began speaking out.

"The bottom line is this: Mr. Jeffrey Epstein, a billionaire, served time in jail and is now a registered sex offender. He has been required to pay his victims restitution, though restitution clearly cannot compensate for the crime," Acosta has said.