Cambodian anti-sex slavery activist resigns after accusations of lying about her own abuse

One of the world's best-known anti-sex slavery activists has resigned from her foundation after questions were raised about her shocking story of being sold into a brothel as a child.

Somaly Mam, a glamorous and energetic Cambodian campaigner, boasts a string of celebrity supporters and has been named a CNN hero of the year, but recently she has been at the centre of controversy.

Her decision to step down follows an investigation by the US-based law firm Goodwin Procter into her personal history, according to a statement released late Wednesday by her eponymous foundation, which did not reveal what the probe had uncovered.

"While we are extremely saddened by this news, we remain grateful to Somaly's work over the past two decades and for helping to build a foundation that has served thousands of women and girls, and has raised critical awareness of the nearly 21 million individuals who are currently enslaved today," the statement said.

Mam says she was sold into a brothel as a child by her "grandfather" and repeatedly raped and abused until, after seeing a friend killed in front of her, she escaped.

"I was completely broken," she told AFP in an interview in 2012.

But the English-language newspaper The Cambodia Daily and Newsweek magazine have reported what they say are inconsistencies in her account.

The Newsweek story, titled "Somaly Mam: The Holy Saint (and Sinner) of Sex Trafficking", said its own interviews with the activist's childhood acquaintances, teachers and local officials contradicted important parts of her autobiography.

The foundation said it had also severed links with another supposed victim of sex trafficking, Long Pros.

Pros's family told Newsweek that she was never a victim of sex trafficking, despite her story that as a young sex slave she was tortured with electric wires and had an eye gouged out by an angry pimp.

Another girl has confessed that her story was fabricated and carefully rehearsed for the cameras under Mam's instruction, the report said.

Mam is no stranger to controversy. In 2011 she allowed a New York Times correspondent to "live-tweet" a brothel raid in Cambodia -- a move slammed by other campaigners as a PR stunt.

She also takes a controversially hardline stance that all sex workers are victims.

Her foundation said that despite its "heartfelt disappointment" it would carry on but on a "revised course".

"Our work changes lives and we remain dedicated to it," the statement said.

There are more than 34,000 commercial sex workers in Cambodia, according to a 2009 government estimate.