The US author of hit books based on the writer's life as a male prostitute and drug addict is actually a 40-year-old woman, her ex-partner has said.
Sarah, LeRoy's first novel, was published in 2001
The persona of JT LeRoy was a hoax created by writer Laura Albert in a bid to have her work recognised, her former partner Geoffrey Knoop has said.
He said keeping her identity secret led their relationship to break down.
The books, such as Sarah and The Heart Is Deceitful Above All Things, secured "author" JT Leroy a cult following.
His celebrity fanbase included Winona Ryder and Courtney Love, while film-maker Gus Van Sant said he had developed a close working relationship with Mr LeRoy, who worked on the script for the director's award-winning film Elephant.
"There was a real solid year when I was talking to him every day for at least an hour, sometimes five hours," said Van Sant, who spent hours on the phone talking to the author.
Winona Ryder is reported to be a fan of the mystery author
The Heart Is Deceitful Above All Things has been adapted for film while Sarah is currently in development.
In recent months, the US press has begun to question the true identity of Mr LeRoy, with suspicions falling on Ms Albert - the woman who claimed to have discovered the teenager on the streets of San Francisco in 1993.
According to Mr LeRoy's widely publicised "life story", Dr Terrence Owens, a psychologist who treated him, encouraged him to write. By 2000, he was being hailed as a literary star.
Dr Owens has refused to discuss Mr LeRoy's identity, citing patient confidentiality - but admitted to the New York Times that most of their sessions were conducted over the telephone.
Geoffrey Knoop says the ruse began back in 1996, with Ms Albert believing she was more likely to win recognition as an author as a teenage boy, rather than as a 30-something woman.
When Mr LeRoy began appearing at celebrity parties - usually wearing dark glasses, a wig and a hat - and always with Ms Albert by his side, it fuelled the mystery surrounding the author.
Earlier this week, the New York Times identified the person who often appeared in public as Mr LeRoy as Mr Knoop's half-sister, Savannah Knoop.
To date, Ms Albert has neither confirmed nor denied that she is the writer behind the LeRoy books. A lawyer for Mr LeRoy, Peter Cane, has refused to comment.
Writer James Frey confessed to making up some of his hit autobiography
Mr Knoop, 39, who split from Ms Albert in December after 16 years, has apologised for his role in the hoax.
"He's wanted to come clean and let JT fade away," said his lawyer Eric Feig, adding that he had secured a film deal to tell his side of the story.
The media furore follows the outcry over author James Frey's A Million Little Pieces last month.
Talk show host Oprah Winfrey accused Mr Frey of betraying his readers after it emerged he falsified elements of his best-selling memoir about his battle with drug addiction.