Sex abuse counsellors say girls as young as nine are the victims of child sex trafficking within New Zealand.
One story has emerged of a nine year old who was tied up by her mother and forced to submit to men.
Researcher Natalie Thorburn told Larry Williams she has been speaking with victims.
"Often the quite bad perpetrators are previously boyfriends and insisting that they do things they don't want to do and using violence and coercion when they don't."
Thorburn said New Zealand girls are being forced to sell their bodies to men.
"In any situation where young people are being raped repeatedly by a number of men so that one person can make a profit form it is a problem. It's impossible to gauge the extent of the problem, it is kept secret and it is hidden."
• Phone the police on 111 or ask neighbours of friends to ring for you.