Senior cabinet minister Megan Woods found out about sexual assault allegations at a Young Labour summer camp more than a week before the prime minister learned about the matter from reporters.
Newsroom has reported a 20-year-old man allegedly assaulted four 16-year-olds - two males and two females - by putting his hands down the pants of at least three of them during a party on the second night of the camp near Waihi on February 10.
The man - not believed to be a member of the party - was ejected from the camp the next day.
And late on Tuesday it was revealed there had been a similar allegation of assault at a previous Labour summer camp.
Party general secretary Andrew Kirton told One News" "I'm aware of an individual... I spoke with today about their experience at a previous event."
No details were given. Newshub reported the previous event was believed to have involved a camp two or three years ago.
A spokesman for Energy Minister Dr Woods, on Tuesday confirmed she got a Facebook message about the most recent incident earlier this month and immediately contacted Mr Kirton.
"Two hours later she heard from the general secretary that he had been in touch with the young person and the situation was being handled appropriately," the spokesman said.
Mr Kirton did not tell police, the teens' parents or Prime Minister Jacinda Ardern, saying it was a matter of confidentiality.
He said he would have backed the teens if they had wanted to press charges.
Support had been offered to them the day and week after the incident, but a complaint was later made to a cabinet minister about a lack of follow-up by Young Labour, he told Radio NZ.
Ms Ardern - who was blindsided when asked about the allegations during a press conference on Monday - on Tuesday admitted the Labour Party was slow to offer follow-up support to the teens through the Sexual Abuse Help Wellington service.
Ms Ardern also admitted it wasn't appropriate for alcohol to be at the camp, but camp-goers had brought it along, she told TV3's The AM Show.
She denied it was a problem that she had only found out about the alleged assault on Monday. The more important issue was whether the teens had been supported properly, she said.
The prime minister also rejected suggestions party officials should have reported the incident to police against the wishes of the teens.
Mr Kirton on Monday apologised for the distress caused and said a review was under way into the policies and processes around the annual camps.
THE TIMELINE AS WE KNOW IT:
* February 9, 2018 - Prime Minister Jacinda Ardern speaks at the opening of Young Labour's "Summer School" camp in Waihi.
* February 10 - A 20-year-old man allegedly sexually harasses or assaults four 16-year-olds - two males and two females - during a camp event.
* February 11 - The man is thrown out and the victims offered support. Shortly after Labour's general secretary Andrew Kirton is informed.
* March 3 - Follow-up offer of professional help offered to victims, according to Mr Kirton.
* March 4 - Energy Minister Megan Woods receives complaint about lack of response by Young Labour and contacts Mr Kirton, who says the matter is being dealt with "appropriately".
* March 12 - Newsroom publishes the allegations and Ms Ardern is blind-sided by media questions. The party issues a statement saying it is "extremely disappointed" about the incident and launches a review.
* March 13 - Ms Ardern accepts the party was too slow to offer support but says she won't sack Mr Kirton.