'We took too long' - Jacinda Ardern on alleged sex assaults at Young Labour camp

Questions are being asked why police and parents weren't told about claims of sexual assault at a Young Labour camp.

Appearing on The AM Show on Tuesday, Prime Minister Jacinda Ardern says her officials were respecting the victims' wishes - but admits it's taken too long to handle the issue.

"I think we took too long because there was a bit of a delay between reaching out and responding with appropriate services," she says.

The Labour Party has confirmed "highly inappropriate" behaviour occurred at its summer camp after four young Labour supporters were allegedly sexually assaulted during a wild party last month.

Newsroom reports witnesses as saying there was "a mountain" of alcohol at the camp and many people, including a 15-year-old boy, were drinking.

A drunken 20-year-old man allegedly put his hand down the pants of at least three young people.

Labour Party general secretary Andrew Kirton told Radio New Zealand's Checkpoint it was the victims' decision not to speak to police. That's why the Labour Party did not inform the parents of the victims about the incident either.

But despite attending the camp, Ms Ardern claims she also was unaware about the alleged assaults and only heard about them on Monday.

"My view is the more important thing was dealing with the issue," she told The AM Show.

"That was the priority of the Party leadership and I support that. So it doesn't bother me that I found out yesterday."

A review is now underway into the camp's procedures, but Ms Ardern has blamed the participants for bringing the alcohol to the camp.

"The very fact that we had people of that age, and that even though alcohol wasn't provided it was present - that wasn't right either," she says.

"So yes there are things that have certainly gone wrong."

The perpetrator has been banned from future Labour Party events.

Police say it is aware of the media reports.

"We encourage anyone with information they wish to discuss with police, or matters they wish to report, to contact us.

Newshub.