Prime Minister Jacinda Ardern says she's "very disturbed" about allegations of harassment and sexual misconduct at a Young Labour camp last month.
"I expect young people, and indeed anyone, attending our camps can do so knowing the environment is safe," she said.
Two young men and two young women were assaulted by a 20-year-old man at Young Labour's summer camp in Waihi, according to Newsroom.
Ms Ardern was questioned on the allegations at her weekly post-Cabinet news conference on Monday afternoon, but said she was not aware of them and would investigate further.
In a statement on Monday evening, she said: "I've sought assurances that everything is being done to support the complainants. I've also asked the party to take every step possible to ensure that our events are safe for everyone who attends in the future.
"I understand this work is already underway, and started as soon as the complaints were received."
Despite the Prime Minister not being made aware of the allegations, Labour's head office was made aware of the incident shortly after it took place.
Labour Party general secretary Andrew Kirton said the camp's organisers notified him of the incident "in the days following the event".
He said the perpetrator has been banned from future Labour Party events, and an external review of policies and procedures is underway to "ensure a situation like this is never repeated".