Last year, France passed a law making it illegal to pay for sex - but not to sell it. The legislation was aimed partly at protecting sex workers from prosecution, but many of them say it is simply driving them further underground and exposing them to far more danger. Transsexual prostitutes who work in Paris's Bois de Boulogne, a large park just west of the capital, are disproportionately affected. FRANCE 24 went to meet some of them and listened to their harrowing stories of violence. A programme prepared by Patrick Lovett and Christopher Davis.