(CNN) - Hundreds of Nigerian women have been trafficked into Paris as sex workers, lured by the promise of a new life only to find themselves in a cycle of abuse and exploitation.
Inside each vehicle, a young woman sold by the hour as her madame stands-by.
The women are physically branded with scars that identify them back in Nigeria as cursed women.
In 2017, the UN International Organization for Migration said there’d been a nearly 600-percent increase in potential sex trafficking victims arriving in Europe through Italy since 2014 and 80% of them were Nigerian.
A nighttime exchange in Paris' largest park, the Bois de Vincennes with just a nod a prostitute is lead into the bushes.
In France it is buying sex rather than selling it that is illegal, but the police say that most of the women who work at the Bois de Vincennes are slaves.
By day the park is a beautiful spot, popular with dog walkers and boules players.
However, by night it becomes a place where men can buy sex for very little.
Police believe 150 sex slaves work in the park.
Local charities say the women who walk these streets are getting younger and that their apparent freedom is an illusion.
Liberation workers say the women have no access to their documents and they have lost their identity.