Police are investigating the sexual assault allegations about the Young Labour summer camp.
Allegations emerged this week that a 20-year-old man allegedly sexually assaulted four people aged 16-18 at a camp in Waihi last month.
Originally police has not been contacted about the alleged assaults.
Earlier today, Labour Party general secretary Andrew Kirton confirmed one of the teenagers had spoken to police about the incident.
"I'm now aware that one of the victims has contacted police about this situation. I learnt that yesterday," Mr Kirton said on TVNZ 1's Breakfast this morning.
"That has our full support. I’ll do whatever it takes in terms of providing information."
The investigation will be overseen by Detective Superintendent Chris Page, police said in a statement.
Assistant Commissioner (Investigations) Richard Chambers said today the investigation will be overseen by Detective Superintendent Page, and encouraged anyone with information to come forward, if they felt comfortable.
"Our priority is to ensure that anyone who wishes to speak with us can feel comfortable in doing so, and to ensure that appropriate support services are available," Mr Chambers said.
"We will not be publicly confirming any matters regarding those who may approach police, or complaints that may be received, to ensure that individuals can feel confident in speaking to us."
They would not be putting a time frame on the investigation.