'No clue'
Unicef estimates that there could be as many as 300,000 restavek children in Haiti, thousands living with the constant threat of violence.
"There is physical abuse, psychological abuse and there are cases of rape, and there are children who actually die from the abuses," says Julie Bergeron, Unicef head of child protection in Haiti.
She says that parents are often unaware of how their children are being treated.
"Someone approaching the family will often say to parents that their child will have a better life," she says. "And often the parents do not have any feedback, they don't know what is happening.
"If they do have, it is through he intermediate, and they will say 'your child is doing fine'. So the parents have no clue."
Jean Robert Cadet, founder of the Restavek Foundation, knows the life of what he describes as "child slavery" only too well.
At the age of four he was given to another family soon after his mother died. For the next 16 years he slept under a kitchen table, was forbidden to smile, laugh or speak unless spoken to, and endured sexual abuse and savage beatings.
Thirty years later, he says, the abuse of restavek children in Haiti continues.
"They use a cow hide whip. One hit will split your skin open," he says.
"Some families who own these children, they still use cheese graters - you will find they have two of them.
"One for the normal cooking in the kitchen, and if they have an old rusty one, they use it to punish the child. The child has to kneel on a cheese grater after the beating."