A teenage girl who believes she was one of the first victims of the Roast Busters says she laid a complaint with police two years ago, but no action was taken.
The girl says she was sexually assaulted by members of the Roast Busters - a group of Auckland teens who boast of having group sex with drunk girls then name their victims online - in 2011, when she was just 13.
The girl, who is now 15, told 3News that once she told her family about what had happened, she laid a complaint with police.
However, she said police told her there wasn't enough evidence for charges to be laid.
Police have previously said they couldn't lay charges against the Roast Busters group because none of the girls have laid a complaint.
In a statement on Wednesday night, police confirmed they did receive a complaint in December 2011 and an investigation was launched.
"Whilst this was a distressing situation for the girl and her family, police determined that there was not sufficient evidence to bring a prosecution," the statement said.
The complaint is still part of the continuing investigation and should new supporting evidence come to light, the decision in this case not to prosecute will be reviewed, police said.
Police began investigating the group about two years ago.
The Roast Busters' Facebook page was revealed by 3News at the weekend, sparking public outrage and calls for police to take stronger action.
Rape groups say the boys should be charged with stupefying and sexual assault against minors.
Police have since spoken again to two members and the investigation appears to have been re-invigorated. A senior detective from another police region has been brought in to work on the case.
Vigilante groups have popped up on the internet, threatening to dish out justice to the Roast Busters group.