An American woman accused the online influencers Tristan and Andrew Tate in a lawsuit on Monday of luring her to Romania, conspiring to coerce her into sex work and defaming her after she gave testimony to the Romanian authorities.

The civil complaint, the first suit filed in the United States against the Tate brothers, includes details about the accusations that led to their arrest in Romania in 2022, some of which have been kept confidential. The brothers have been battling cases in Romania as well as in Britain, including accusations of human trafficking, money laundering and sex crimes.

The Tate brothers, who are known for promoting an antagonistic, anti-feminist brand of masculinity, have vigorously denied all of the accusations against them, arguing that their wealth and outspokenness has made them targets.

The brothers sued the woman who brought the suit, identified in court documents as Jane Doe, for defamation in 2023, accusing her and another woman of conspiring to defraud and falsely imprison them by giving what they said was fabricated evidence to the Romanian authorities. That information, the brothers said, helped lead to their arrests on charges of trafficking and forming an organized crime group.

The new complaint, filed on Monday in Circuit Court in Palm Beach County, Fla., said the Tates’ defamation lawsuit was part of a campaign to “bully and harass” Ms. Doe into recanting her testimony to the Romanian authorities.

Ms. Doe, 23, and her parents were granted anonymity by the court because of concerns over their safety. She feared being harmed by the Tate brothers or their followers, said Dani Pinter, a lawyer and a senior vice president at the National Center on Sexual Exploitation, who is representing the woman.