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Somaly Mam, in Berlin, introduced her book titled "The Silence of Innocence" in which she describes her own way out of the prostitution. (AP Photo)

Prostitutes are working the streets of Phnom Penh. Despite recent efforts by the Cambodian authorities to curb the country's huge illicit sex industry, the trade is continuing to thrive. While some brothels have been closed, others have been driven underground.

Cambodian law does not explicitly define prostitution as illegal, but commercial sex is frowned upon by authorities who routinely launch sweeps to clean up the streets. Every year in Cambodia hundreds of young girls are kidnapped by human traffickers and sold into brothels. Many endure years of mental and physical torture and they are forced to receive up to twenty customers a day.

Meanwhile, growing numbers of sex workers are moving to beer gardens, karaoke clubs and bars. While some so-called "bar-girls" choose sex work to escape poverty, a large proportion of brothel-based sex workers are the victims of human trafficking.

Founded by a former sex slave, The Somaly Mam Foundation was set up to rescue and rehabilitate victims of human trafficking. Somaly Mam blames organised crime networks, and corrupt officials, for Cambodia huge trafficking problem.

“Organized crime networks have set up a people trafficking system. They go from village to village looking for girls. Sometimes they use marriage to take them or they promise them good jobs in Phnom Penh with good salaries. Because many victims are poorly educated they fall for the trick and when they come to the city they get locked in a brothel”, she said.

The Somaly Mam Foundation has rescued over four thousand sex slaves from brothels throughout Cambodia since it was set up in 1996. It is currently caring for over 250 girls in three centres around Cambodia. More than half of them are under 18 years of age and most of the girls endured years of torture and abuse in brothels.

Vann Sina is keen to tell her story, how she was lured from Vietnam and imprisoned in a Cambodian brothel when she was just 13 years of age.

“I was beaten a lot and had to serve many clients. If I refused they would tortured me with electric shocks or force me to eat hot chillies. They locked me in an underground cellar and if I didn’t receive 15 to 20 clients a day, they would beat me up or torture me some more,” she said.

Life in a brothel is a living hell, says Somaly Mam as she recalls the years of abuse that she also endured.

“If you have lived with terrible experiences, or a bad situation, it does not mean that you are bad. We have to take our terrible experiences, shape them and turn them into something positive. But we have to remember what happened to us and never forget it. We have to help other victims and then they will help you by giving you love,” she said.

Sex work takes a huge physical and mental toll on the women involved. As well as the threat of AIDS and other sexually transmitted diseases, many victims are psychologically damaged by their experiences. Doctor Ma Lay says most of the girls need years of therapy.

“Most of the girls who come to the centre have severe mental problems. They get angry easily, they shout a lot and many of them just want to die. And when we face this kind of situation we help them with regular counselling sessions where we try to encourage them to appreciate themselves and the value of life - and that takes a lot of time," she said.

The Somaly Mam centre creates a loving environment where the girls can make new friends and try to recapture their lost childhood. As well as treating victim's mental and physical injuries, the Somaly Mam Foundation provides further education and job training.

Vocational courses are offered alongside formal classes to help the girls find employment after they leave the centre. But the main aim is to teach the girls that their lives have meaning and that they can have a bright future. Human trafficking is the world's third most profitable criminal enterprise and there are more slaves today than at the height of the trans-Atlantic slave trade. These girls represent the lucky few who managed to escape a fate that awaits thousands more girls in Cambodia and around the world unless greater efforts are made to stamp out this trade.

Information for this report was provided by APTN.