During Jeffrey Epstein's first spell in jail, a 13-month sentence for soliciting sex from an under-age girl, prison records show one woman visited him at least 67 times.
That woman was Nadia Marcinko. Marcinko was Epstein's main girlfriend for seven years - his most significant partner after Ghislaine Maxwell - and in later years, an assistant pilot of his private plane.
She is comparatively unknown to the public, but she may soon find herself in the spotlight.
Marcinko is one of four women who were named as Epstein's "potential co-conspirators" in a 2008 plea deal that granted them immunity from prosecution. Now, two of those women - Epstein assistants Sarah Kellen and Lesley Groff - are about to be questioned by US legislators. One congresswoman wants all four, including Adriana Ross, another Epstein assistant, and Marcinko, to be investigated, despite the plea deal.
Marcinko has never been accused of, or charged with, any crime. Her lawyers say she is one of Epstein's victims. But girls in Palm Beach, Florida, whose testimony about their abuse when they were under age led to Epstein's conviction in 2008, told police that Marcinko participated in that abuse.
The BBC has spent months interviewing those who have met Marcinko, and scrutinising every email we could find between her and Epstein in the files, to try and build a detailed picture of her role in the disgraced financier's life.
The emails reveal Epstein and Marcinko wanted to start a family together, we have discovered. The BBC has also found evidence suggesting that over many years, he asked her to recruit other women to help satisfy his sexual desires and she complied.
But the emails also expose deeply coercive tendencies on the part of Epstein. Marcinko later told investigators that he was physically violent, choking her, and throwing her down a flight of stairs. We have had access to her account to investigators via a document that was released - heavily redacted - by the US Department of Justice in January. Marcinko's name is not visible, but the five pages of testimony match in every detail what we know about her from other sources.
The BBC contacted Marcinko for comment, but she did not reply. Since Epstein's death in prison in 2019, awaiting further sex charges, she has disappeared from public view.
The calls for an investigation into Marcinko have raised important questions about whether a victim of sexual coercion can also be deemed an accomplice.
Marcinko was born Nadia Marcinkova into a comfortably-off, respected family in Slovakia. She told federal investigators who interviewed her after Epstein's death that she had first met the financier in New York in 2003, when she was 18, at a birthday party for Jean-Luc Brunel. A close friend of Epstein's, Brunel ran the New York branch of modelling agency Karin Models. Marcinko said she had been working for the agency in Paris, and Brunel brought her to the US a few weeks before his party, on a visa he had arranged.
This seems to be backed up by email chains the BBC has traced in the Epstein files, which reveal that for many years afterwards, Marcinko and Epstein celebrated the same date - 17 September - as their "anniversary".
Marcinko was an unlikely international model, says a primary school classmate who we are calling "Jozef". Though she was beautiful, she was very shy - "what we call šedá myška, a little grey mouse".
She began modelling as a teenager, with assignments soon taking her to Japan and Taiwan, she once told a Slovak newspaper.
A few days after she first met Epstein at Brunel's party, Epstein invited her to his mansion in Palm Beach, Marcinko told investigators. And from there, flight logs confirm, she went on to his private Caribbean island, Little St James.
She was legally an adult, but the imbalance between them in power, wealth and age was huge. Epstein was already 50, so 32 years her senior.
Because Brunel sponsored her visa, and because Epstein bankrolled Brunel's agency - to the tune of a million dollars - she felt, she later told investigators, that "Epstein could have her deported with a single phone call to Brunel".
She travelled with him constantly, she told investigators. And emails, both in their tone and content, suggest they rapidly became a couple. Ghislaine Maxwell was still Epstein's close friend, and was finding other women for him, but their sexual relationship was coming to an end, our research suggests. Marcinko was now his main girlfriend, the emails show.
But though there is plenty of sentiment in the emails - and Epstein writes to someone else in 2009 that "I am in love with nadia" - the exchanges also reveal how domineering he was.
An email from that year gives a flavour of what he seems to have expected from her.
"I want you to learn how to cook eggs. scrambled poached over easy... I want you to learn how to run a house.. I want no arguments during the monday to friday, week… I want you to read one of the hundred great books every month… I want beautiful things only in the house. you cannot put anything in, without letting me see it first. J"
After his death, Marcinko told investigators Epstein had controlled every aspect of her life, including her weight and clothing. She said he had forced her to have multiple plastic surgeries and physically abused her.
We have not found any direct mention of those incidents in their email exchanges, but that does not mean they do not exist somewhere in the files. In one email we found, she accuses him of "abusive partner behaviour".
And there is repeated reference to Epstein's expectation that Marcinko will scout for other women or girls for him.
In 2006 she wrote: "What do you imagine is a fun sex thing? I will do what I can, even though if this is simply about you having sex with someone else, I don't know how it makes our relationship better. I will try to find girls whenever we are in New York."
Some messages suggest Nadia knew Epstein preferred his women young. But we have found no evidence in the files that she ever introduced him to girls who were under age. Nevertheless even recruiting adults, through deception, for exploitative purposes, can be defined as trafficking.
That same year, 2006, Epstein emailed a request to Brunel to put Marcinko on the payroll of Brunel's new modelling agency, MC2, and pay her $50,000 (£37,014) a year. It is not clear what the salary was for as Marcinko was no longer working as a model. But whatever she was expected to do, she was clearly uncomfortable about her dependency on Epstein.
In one email to him that year, she wrote: "Since I met you, my life revolves around you, there is nothing else I have and it makes me feel very uneasy."
But in 2009, at the same time she was visiting Epstein in jail, she appears to have begun to lessen her financial dependence on him, by taking to the air. Epstein paid tens of thousands of dollars for her to train as a pilot, emails between them show, which she apparently did with great enthusiasm, promoting herself on social media as "Global Girl."
"That was money-making for her, because she was invited to fly a lot of aeroplanes and do a lot of videos," says aviation journalist Christine Negroni, who says she met Marcinko in 2013.
"Nadia was delightful. She was charming company… And she worked very hard attending flight schools to get her certificates, one after another… These are not easy accomplishments."
Despite her new apparent independence, Marcinko's relationship with Epstein continued after his release from prison in July 2009, emails show. It seems to have even intensified.
By October of that year they were trying to have a baby together, the emails suggest.
And she maintained her role as a scout, the files reveal. In one email that year, she asks his opinion of a specific woman she says has offered to come over from eastern Europe.
But in 2010, they finally split up after he had been particularly violent towards her, she told the investigators.
The following year, according to the account she gave them, she got a new work visa based on her own aviation job.
She and Epstein clearly remained friends, though. She co-piloted his private jet on some flights to his island from 2012. In 2013, he arranged for her to get a job as a flying instructor for the company of entrepreneur Dean Kamen, inventor of the Segway. Messages between Marcinko and Epstein in 2015 confirm what she told investigators - that he agreed that year to double whatever income she earned from other sources.
We asked Kamen's company, DEKA, for a comment about its association with Nadia Marcinko, but it did not reply. A spokesman for Kamen has previously said the inventor deeply regrets having any interactions with Epstein, and had no involvement in, or knowledge, of his crimes.
But, though Marcinko appears to have been loyal to Epstein for years, in 2018 she finally switched sides. A document in the files describes how she began to co-operate with the FBI that year in its investigation.
The following year, Epstein was jailed again while he awaited sex trafficking charges. In return, four years later the FBI supported Marcinko's application to stay in the US after her visa ran out in 2022. The agency said she had been "recruited, harbored and obtained by Jeffrey Epstein and others for purposes of a coercive sexual relationship".
Since then, Marcinko has disappeared from public view. Social media posts suggest she had been, at least up until last year, an active member of a Zen Buddhist centre in New York. Previously, her lawyer has said that she wants to eventually speak out about her victimisation and help other survivors, but is currently "working on her healing".
But the immunity given to Marcinko and the other three women in the 2008 plea deal is now being questioned. US congresswoman Anna Paulina Luna, a Republican member of the House Oversight Committee, said in February, apparently after seeing unredacted Epstein documents: "All of these women engaged in the trafficking of minors as adults. They were working and complicit with Jeffrey Epstein's operation."
Though Kellen and Groff are about to give testimony, it appears that the committee has yet to decide whether to call Ross or Marcinko.
The judgement as to how far a victim can also be termed an accomplice is nuanced, says Bridgette Carr, professor of clinical law at Michigan University, who has worked extensively with victims of human trafficking.
She tries to discern whether a victim has continued to commit crimes after escaping the control of a perpetrator, bearing in mind the control may continue even if the perpetrator is not physically present in the victim's life.
"The line I draw is whether the victim has ever been away from the power and control of the perpetrator."
The question is "whether it's reasonable that [the victim] would believe that that perpetrator [still] has power over them".
What choices Nadia Marcinko had, if any, in the course of her long association with Jeffrey Epstein, it is impossible for an outsider to know. Documents in the files provide only glimpses of her life. But one email from 2012 is perhaps more revealing than most.
"I do not want to be with you, but it upsets me to see you use the same exact patterns to seduce, manipulate, and ultimately control and hurt other girls. I don't even like them and I actually feel guilty about knowing how they will end up," she wrote.
"I know what you are capable of and I will always be protective of you out of pure loyalty and stubbornness, but my conscience is far from clear."
