By Emma Batha

LONDON (Thomson Reuters Foundation) - After escaping years of sexual slavery, Jennifer Kempton could not look in the mirror without being taken back to her dark, traumatic past.

On her neck was tattooed the name of one of her traffickers along with his gang's crown insignia. Above her groin were the words "Property of Salem" - the name of the former boyfriend who forced her into prostitution nine years ago.

"Slaves have been branded for centuries and it's just evolved into being tattooed. It's happening all over the world," said Kempton who suffered horrific brutality during six years working on the streets of Columbus, Ohio.

Today the tattoo on her neck has been transformed into a large flower "blooming out of the darkness". Three other brandings have been masked with decorative, symbolic motifs.

Two years ago Kempton, now 34, set up a charity called Survivor's Ink to help others who have escaped enslavement get their brandings covered up or removed.

"It was very empowering for me so I wanted to pay forward that liberation to other girls in my area who had been branded like cattle, just like I was," Kempton told the Thomson Reuters Foundation.

Most requests for help come from women in the United States, but the grassroots project increasingly receives applications from other countries including Canada, Britain, Australia and Croatia. Some of the stories are very disturbing.

Kempton said they recently helped a woman in Britain whose mother had carved the word 'whore' into her leg when she was a child and sold her. Every time the word faded it was recarved.

Globally some 4.5 million people are trapped in sexual exploitation, according to the International Labor Organization, generating an estimated $99 billion in illegal profits a year.

SOLD AND RESOLD

Kempton says there is a major misconception that women trafficked into prostitution are brought in from poor countries.

In the United States an estimated 80 percent of women trafficked into prostitution are U.S.-born citizens, Kempton said, ahead of the Trust Women conference in London this week which will focus on human trafficking and slavery.

Kempton wants tougher penalties for traffickers and improved training for police to better identify and help victims.

She is also an advocate of an approach adopted by Canada and some European countries which criminalizes men who buy sex rather than the women trafficked into prostitution.

Describing her downward spiral, Kempton refers to a dysfunctional background in which she was raped at the age of 12. In her 20s, after a series of abusive relationships, she thought she had finally met her "Prince Charming".

But he soon got her addicted to heroin, put her on the streets and plied her with crack cocaine so she could work longer hours.

At one point she was kidnapped by armed men who locked her in a hotel room to have sex with a stream of men.

After escaping to her "boyfriend" she discovered she was pregnant with his child, but when her body grew and her earnings shrank he sold her to a couple of drug dealers.

After the birth she was sold again "to the most violent gang in Columbus".

    The turning point came in April 2013 after a brutal rape.

    During a prolonged attack she was beaten beyond recognition and raped with a knife. As she fled the house bleeding she begged two men for help but they laughed and locked their door.

"The sound of the door locking just echoed in my mind. I was locked out of society, I was not seen as worthy of help," said Kempton. Afterwards she tried to hang herself, but the rope snapped.

In her despair, she heard a voice telling her she had a purpose in life "and it wasn't to die in the basement of a crackhouse".

Survivor's Ink has so far provided grants to help around 100 women cover up their slavery brandings.

    "It's always amazing to see the look on their face when they no longer have to look at this dehumanizing mark of ownership and violence," Kempton said.

"Sometimes I'll get a call a few days later with someone just bawling their eyes out saying 'Oh my gosh, I can actually look at my body. It's my own again.'."

(Editing by Belinda Goldsmith; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, which covers humanitarian news, women's rights, trafficking, corruption and climate change. Visit news.trust.org to see more stories.)