Virginia Roberts Giuffre has said she is "not suicidal" in case something happens to her because "many evil people" want her silenced.
The 36-year-old has repeatedly said she was trafficked by convicted sex offender Jeffrey Epstein and pressured into having sex with Prince Andrew in 2001 when she was 17.
In response to a tweet written about her that said "F.B.I. will kill her to protect the ultra rich and well connected...", the mother-of-three informed her followers she was not suicidal in "no way, shape or form".
She added: "If something happens to me - in the sake of my family do not let this go away and help me to protect them. Too many evil people want to see me quieted."
Prince Andrew has strenuously denied he had "any form of sexual contact or relationship" with Mrs Roberts Giuffre, adding "any claim to the contrary is false and without foundation".
He has said he has no recollection of meeting Mrs Roberts Giuffre and that a photo appearing to show them together may have been doctored.
In her first UK interview earlier this month on BBC's Panorama, she said of the duke: "He knows what happened. I know what happened, and there's only one of us telling the truth."
Mrs Roberts Giuffre told Panorama about their alleged meeting in the London nightclub Tramp.
She said: "He is the most hideous dancer I've ever seen in my life.
"I mean it was horrible and this guy was sweating all over me, like his sweat was like it was raining basically everywhere I was just like grossed out from it but I knew I had to keep him happy because that's what Jeffrey and Ghislaine would have expected from me."
Then known as Virginia Roberts, she says she was brought to London by Epstein and his partner Ghislaine Maxwell in 2001 and was introduced to the prince.
Later that evening, she said she was instructed to have sex with the duke.
The interview was aired after - but recorded before - Andrew's own interview on BBC Newsnight.
Andrew used his Newsnight interview to counter her claims that he sweated heavily during one of their encounters. He told the programme he had lost the ability to sweat following his service in the Falklands War.
His responses in the interview were widely criticised, with many companies who had an association with his charity projects withdrawing their support.
Within a week, Andrew released a statement confirming that he would be stepping back from his public duties.
Mrs Roberts Giuffre had also told Panorama that it was "BS" to say the photo of the two of them had been doctored.
She said: "The people on the inside are going to keep coming up with these ridiculous excuses. Like his arm was elongated or the photo was doctored, or he came to New York to break up with Jeffrey Epstein. I mean, come on, I'm calling BS on this, because that's what it is."
In response to the Panorama interview, Buckingham Palace said the duke "unequivocally regrets his ill-judged association with Jeffrey Epstein" and "deeply sympathises with those affected who want some form of closure".
They said "it is emphatically denied that the Duke of York had any form of sexual contact or relationship with Virginia Roberts. Any claim to the contrary is false and without foundation".