Another person has contacted the Labour Party saying they too were sexually assaulted at a Labour event several years ago.
Labour has already apologised to four teenagers who were sexually harassed by a 20-year-old man at a Labour youth camp in Waihi last month.
It's understood the 20-year-old put his hands down the pants of three of the teenagers.
Prime Minister Jacinda Ardern has said there were clear failures in the way the party handled this year's incident - saying follow-up services and support for the teenagers were delayed.
Labour general secretary Andrew Kirton said another person came forward today saying they experienced sexual harrassment at a separate Labour event.
"I offered our support, and our support if they wanted to take that to the police or to take it further, now or at any point in the future."
Mr Kirton said the new complaint related to alleged offending of a similar nature as to what occurred in Waihi. It happened within the last 10 years, he said.
Labour has ordered an external review of its events and Mr Kirton said the party needed to ensure that it was a safe organisation for young people to belong to.
"The focus of the review that we'll be conducting to make sure that we take the actions necessary to make that happen and everything's on the table.
"Not just alcohol, not just the basics, but making sure that across the party - Young Labour and other parts of the party - it is a safe environment for people."
He was concerned there was a broader problem with Labour's events.
"That's something we will be looking into.
"This has happened today, I've been made aware, so we're going to review the situation and probably have more to say on it."
Agency backed Labour's decision
Earlier today, a sexual abuse support agency says it backed Labour's view not to tell parents or police about the most recent sexual assaults.
But it was not asked for that advice until nearly three weeks after senior party officials were made aware of the incident.
Party general secretary Andrew Kirton said the party "took the call' not to tell anyone else initially, because they wanted to allow the victims to make those decisions.
When asked who gave the advice not to report it to police, Mr Kirton said "we discussed our approach with a couple of agencies".
That included HELP in Wellington, "who deal with these sort of situations, and we took the view that the appropriate course was to let the young people themselves take that lead", he said.
HELP chief executive Conor Twyford said she was contacted by Mr Kirton last Monday.
"We endorsed Labour's approach of keeping the circle small. It is absolutely up to the people who have experienced sexual harm to decide what they want to do next," she said.
"So we're looking for a survivor-led approach, and that's what I ascertained Labour was doing when Andrew [Kirton] contacted me last week."
However, there should not have been a gap between the incident and professional services getting involved, she said.
"People affected should be put in touch straight away with specialist support so they get what they need at the earliest opportunity.
"Sometimes people say they're okay immediately after, and sometimes they're not ... and it takes a while for people to realise they're not okay."
Prime Minister Jacinda Ardern said there were clear failures in the way the Labour Party handled the situation but Mr Kirton would keep his job.
She acknowledged senior party members knew, and police were not told.
"This was a party function and so of course the senior members of the party knew.
"The advice they had from those who specialise in this area - and we are not experts - was to be mindful of the wider circle who was aware in order to make sure that they were protecting victims and acting in the best interest of victims," she said.
"My understanding [was Mr Kirton] was acting at the will of those involved."