When Jeffrey Epstein was found dead in an apparent suicide in his jail cell in August, authorities were forced to shift their focus onto his alleged accomplices.
"Let me assure you that this case will continue on against anyone who was complicit with Epstein," US Attorney-General William Barr said.
"Any co-conspirators should not rest easy. The victims deserve justice and they will get it."
Epstein, a convicted sex offender, was awaiting trial for sex-trafficking charges over the alleged sexual abuse and exploitation of dozens of women, many of whom say they were underage at the time.
For decades, British socialite Ghislaine Maxwell was one of the disgraced financier's closest confidantes. And his alleged victims have accused her of being deeply involved in Epstein's criminal activities.
Multiple women have accused her of being Epstein's "primary co-conspirator" and "madame" whose job it was to recruit young women into his orbit.
But the 57-year-old has not been seen in public for months.
"No-one knows where she is," a lawyer for one of Epstein's alleged victims said this week.
"She's done the greatest disappearing act known to man — or woman."
Prince Andrew's ex-girlfriend, Lady Victoria Hervey, described Ms Maxwell as "a little bit like a James Bond character".
"She's quite a unique person and I just don't believe that anyone will find her," she said.
Authorities have never charged Ms Maxwell over Epstein's crimes, though she has been sued in civil lawsuits. She "strongly denies" all allegations.
Who is she and when did she meet Jeffrey Epstein?
The youngest child of media tycoon and fraudster Robert Maxwell, Ghislaine Maxwell was born into exceptional wealth, but has often been trailed by controversy.
In 1991, her father's body was found floating naked in the sea after he apparently fell overboard from his yacht off the Canary Islands. It later emerged he had plundered hundreds of millions of pounds from his companies' pension funds.
After her father's death, Ms Maxwell moved to the United States and was soon photographed with Epstein.
What are the allegations against her?
Several alleged victims said Ms Maxwell facilitated their initial contact with Epstein, often recruiting them under the guise of legitimate employment.
In court documents, which were made public in August, lawyers for Virginia Giuffre said Ms Maxwell was Epstein's "primary co-conspirator" to "procure under-aged girls for sexual activities".
They said Ms Maxwell approached Ms Giuffre at Donald Trump's Mar-a-Lago resort, where she worked as a locker room attendant, and offered her a job.
Epstein, "with the assistance of" Ms Maxwell, then "converted [Giuffre] into a 'sex slave'" from "about 1999 through 2002", the documents alleged.
In an interview with the Miami Herald, Ms Giuffre said "the training started immediately".
"It was everything down to how to give a blowjob, how to be quiet, be subservient, give Jeffrey what he wants," she said.
"A lot of this training came from Ghislaine herself."
Another alleged victim, Joanna Sjoberg, testified Ms Maxwell "approached [her] while [she] was on campus at Palm Beach Atlantic College" in February or March 2001.
Ms Sjoberg said Ms Maxwell recruited her under the guise of a legitimate job of answering phones, a position she said lasted "one day".
She said she was soon instructed by a woman employed by Ms Maxwell "how to massage" Epstein.
Q: Based on what you knew, did Maxwell know that the type of massages Jeffrey was getting typically involved sexual acts?
Q: What was Maxwell's main job with respect to Jeffrey?
Sjoberg: Well, beyond companionship, her job, as it related to me, was to find other girls that would perform massages for him and herself.
Epstein's house manager, Juan Alessi testified he witnessed "probably over 100" female "massage therapists" arrive at Epstein's house.
When asked who would "go out looking for the girls" to recruit, he answered: "Ms Maxwell, Mr Epstein, and their friends, because their friend [would] relay to other friends they knew a massage therapist and they would send [her] to the house".
In a 2015 statement, Ms Maxwell "strongly denie[d]" Ms Giuffre's allegations, saying they were "not new and have been fully responded to and shown to be untrue".
"Ms [Giuffre's] claims are obvious lies and should be treated as such and not published as news, as they are defamatory," she said.
What's her link to the Prince Andrew allegations?
Ms Giuffre said in court documents she was "forced to have sexual relations" with Prince Andrew when she was 17 in "[Ms Maxwell's] apartment" in London.
She said Ms Maxwell "facilitated" this encounter "by acting as a 'madame' for Epstein".
A famous photo of Ms Giuffre and Prince Andrew depicts the Prince with his hand around the woman's waist.
The photo is said to have been taken in Ms Maxwell's London home, with the socialite pictured standing behind the pair.
In what has been called an "excruciating" and "evasive" BBC interview, Prince Andrew repeatedly denied Ms Giuffre's claims, and hinted the photo of them together may have been doctored.
"I have absolutely no memory of that photograph ever being taken," he said.
"From the investigations that we've done, you can't prove whether or not that photograph is faked or not, because it's a photograph of a photograph of a photograph.
"That's me [in the photo], but whether that's my hand or whether that's the position … I have simply no recollection of the photograph ever being taken."
Prince Andrew confirms he saw Ms Maxwell this year
Prince Andrew told the BBC he last had contact with Ms Maxwell "earlier this year" when she "was [in the UK] doing some rally".
UK media has reported Ms Maxwell took part in a four-day charity car rally from London to Monte Carlo from June 6-9, 2019.
This places the pair's meeting prior to Epstein's arrest on July 6 but after US prosecutors announced they were reopening the investigation against him in May.
Prince Andrew said he did not discuss Epstein with Ms Maxwell "at all" during their June encounter.
"There wasn't anything to discuss about him because he wasn't in the news, you know, it was just … we had moved on," he said.
"If there are questions that Ghislaine has to answer, that's her problem, I'm afraid."