The Labour Party has suspended all Young Labour events until an external review is completed following sexual assault allegations.

It's alleged that a 20-year-old man assaulted or harassed four 16-year-olds at Young Labour's summer camp in Waihi last month, which police are currently investigating.

This week a second incident has also come to light, according to the party.

In addition to the suspension, Labour has banned alcohol at any future events when those under 18 are present - and it will take over from Young Labour in planning and running future events.

Prime Minister Jacinda Ardern said in a statement on Wednesday: "It has become very clear to me the extent of our failure to both provide a safe environment for those young people at the Waihi Summer Camp and to properly deal with serious concerns raised by several attendees in relation to sexual misconduct and alcohol.

"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."

The external review will be conducted with help from the Sexual Abuse Prevention Network.

It's yet to be announced who will head the review or when it will commence.

Newshub.