National's Judith Collins says Labour's youth camp scandal has shown up "a crisis of leadership" from the prime minister down.
Ms Collins told Newshub's AM Show Jacinda Ardern had repeatedly called out companies and individuals over sexual harassment allegations.
"I'm very disappointed in Jacinda Ardern," she said.
"It's a crisis of leadership from the prime minister and senior people in the Labour Party who didn't take the action they should have taken."
The Prime Minister says she'll investigate "because that is not the behaviour that I would expect of any Labour function".
Labour has ordered an independent inquiry into allegations four 16-year-olds - two males and two females - were sexually assaulted at a summer camp organised by the party's youth wing.
it's been reported a 20-year-old man put his hands down the pants of at least three of them during a party at the camp near Waihi on February 10.
He was ejected from the camp the next day.
Senior party officials knew about the incidents but didn't tell the victims' parents or the police.
Cabinet minister Phil Twyford, on the same programme, said that was on the advice of sexual abuse prevention groups "so as not to widen the circle and put the victims under even more stress".
Ms Collins rejected that explanation.
"I would rip their throats out for doing that if it was my kid, not physically of course. I can't believe they sat there and said 'Oh well, lets not widen the circle' - why not?
"It's this sort of secrecy that breeds this sort of behaviour."
Police have started an investigation after one of the victims laid a complaint.
Ms Ardern has said the party handled the whole thing "very, very badly".
Since the allegations came to light there have been reports of two similar sexual abuse or harassment claims.
One involves a summer camp several years ago and the other a Young Labour volunteer in Christchurch during last year's election campaign.
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