Ghislaine Maxwell’s disappearance in the wake of Jeffrey Epstein’s suicide has been one of the most mysterious elements of the entire scandal. Now the FBI has reportedly launched a search for answers.

Reuters news agency reported Friday that Maxwell is the main focus of an investigation into people who may have helped facilitate Epstein’s alleged sex-trafficking operation. Maxwell, 58, was once Epstein’s girlfriend and became a key member of his inner circle, with the dead sex offender describing her in 2003 as his “best friend.”

Maxwell has rarely been seen in public since 2016, and hasn’t been spotted at all since Epstein was charged with sex trafficking in July. Her whereabouts have been a matter of intense speculation since Epstein killed himself inside his jail cell in August. The Washington Post reported that she may have been living in a mansion Massachusetts, whereas British tabloid The Sun is offering a $13,000 reward for information.

Two law-enforcement officials told Reuters that Maxwell is the principal focus of the FBI’s investigation, but it’s also seeking information on a wider range of “people who facilitated” Epstein’s actions. The sources are said to have told Reuters that the FBI is following up on leads received from women who contacted a hotline set up after Epstein’s arrest.

Reuters reports the sources refused to identify any other people the FBI is investigating, but they did say that there are no current plans to interview Britain’s Prince Andrew. The prince was a friend of Epstein’s who was forced to step down from his public duties in November because of what he admitted was an “ill-judged” relationship. The sources said Andrew is not considered to have facilitated Epstein, but they didn’t rule out the possibility that the FBI would ask to interview Andrew at a later date.

The FBI and Maxwell refused to comment on the Reuters story, while a spokesperson for the British royal family said that whether the agency interviewed Andrew was “a matter for the FBI.”

Virginia Roberts Giuffre, one of Epstein’s alleged victims who was infamously pictured with Andrew, has said in court filings that Maxwell was responsible for bringing her into Epstein’s proximity, after which she claims he forced her to have sex with him and his friends, including Andrew. A number of Epstein’s alleged victims have said Maxwell lured them into his world to be sexually abused by him and connections.

Giuffre told Dateline NBC earlier this year: “I get approached by this beautiful, well-spoken, well-mannered woman with an English accent... She told me her name was Ghislaine Maxwell, and she said ‘I know this older gentleman who’s looking for a traveling masseuse. He’s super rich, he flies around everywhere. If you want, you can come by for an interview.’”

Giuffre said even after Maxwell ordered her to perform sex acts on Epstein during their first meeting, she went back again because they’d promised they could help her become a professional masseuse.

Maxwell has denied Giuffre’s allegations, and the FBI hasn’t accused Maxwell of any form of wrongdoing.

Prince Andrew denies ever meeting Giuffre.