Sydney: New Zealand’s ruling Labour Party has suspended all events by its youth wing after police opened an investigation into a summer camp where media has reported instances of sexual assault took place.

Police gave few details about their investigation in to the camp at Waihi, in the North Island, in a statement on Wednesday.

But a police spokeswoman told Reuters the investigation concerned allegations reported in the media.

Four teenagers have accused a 20-year-old man of sexually assaulting them during a party at the camp, according to news website Newsroom, which first reported the story.

“As a result of the incidents at the Waihi summer camp we have taken the decision to immediately suspend all Young Labour events,” Labour Party President Nigel Haworth said in a statement.

Prime Minister Jacinda Ardern said in the party statement that “serious concerns” were raised by several attendees “in relation to sexual misconduct and alcohol” at the camp, which are often visited by senior Labour politicians and organisers.

“We failed the young people who told us they had been hurt this failure left them feeling abandoned and I am deeply sorry for that. It’s not good enough, we let them down,” she said.