New research has uncovered some uncomfortable and tragic truths about Kiwi children: New Zealand has a secret world of child prostitution.

“They had accepted that they were worthless, that they were inadequate and that is how they saw themselves,” Social worker Natalie Thorburn, whose Masters studies were discovering the problem, told Seven Sharp.

“Kids were selling themselves for sex from 12, but there was this one instance where this girl was being sold for sex at nine.

“I think if you say to any Kiwi underage sex work, they'd say Thailand, places that aren’t here, places that aren’t in their own backyards.”

She began posting signs asking for young girls to anonymously share their story with her during hour-long meetings.

“They all really all really wanted help, but when they looked for it, they felt judged,” she said.

“I have to take a period of time after hearing them … cry or to feel or to sort of sit with the enormity of those stories.”

‘Yasmin’, whose childhood involved abuse, began selling her body for sex at age 15.

“There were kids as young as 13 -14 selling their bodies,” she said.

“You need the money. And if people are going to abuse you, then you may as well get paid for it sort of thing.”

Warren Ferdinandus from ECPAT, an organisation to prevent children’s sexual exploitation, said New Zealand was “still thinking that it is not a big problem”.