Ghislaine Maxwell, the former girlfriend of Jeffrey Epstein, is suing the late US financier's estate seeking reimbursement for legal fees and security costs, court documents say.
Ms Maxwell's complaint states that she "had no involvement in or knowledge of Epstein's alleged misconduct" and that he had promised to cover her costs.
She also "receives regular threats to her life and safety", it adds.
Epstein had been charged with the sex trafficking of dozens of girls.
He was arrested last year in New York following allegations that he was running a network of underage girls - some as young as 14 - for sex.
He pleaded not guilty. Later, on 10 August, the 66-year-old was found unresponsive in his New York cell. His death was determined to be suicide.
Ms Maxwell, a long-time friend of Epstein, has not been accused by the authorities of wrongdoing.
Ms Maxwell's lawsuit, which is dated 12 March but was made public on Wednesday, claims that "extensive global coverage" of the investigation resulted in her having to "hire personal security and find safe accommodation".
It adds that she "formed a legal and special relationship" with Epstein that obligated the estate to compensate her, and that "assurances" were made but later ignored after she filed a reimbursement claim in November.
Lawyers representing Epstein's estate have not yet commented on the complaint.
Who is Ghislaine Maxwell?
Ms Maxwell is the daughter of late British media mogul Robert Maxwell.
A well-connected socialite, she is said to have introduced Epstein to many of her wealthy and powerful friends, including Bill Clinton and the Duke of York.
She has mostly been out of public view since 2016.
An alleged Epstein victim, Virginia Giuffre, said in a civil lawsuit that Ms Maxwell had recruited her into the financier's circle, allegations Ms Maxwell denies.
Other women have also made allegations that Ms Maxwell was involved. One, Sarah Ransome, told the BBC's Panorama that Ms Maxwell "controlled the girls. She was like the Madam". Ms Maxwell has denied any involvement in, or knowledge of, Epstein's alleged abuses.