The founder of Labour's youth camp programme says he's never heard of harassment at camps before.

Labour has apologised to four teenagers who were allegedly assaulted or harassed by a 20-year-old at a Young Labour summer camp last month.

It's also investigating reports of children as young as 15 drinking alcohol at the camp.

READ MORE:Ardern admits errors in camp falloutLabour apologises, confirms inappropriate behaviour at camp

Former Labour Party president Mike Williams told Mike Hosking the alleged behaviour is unacceptable and unprecedented.⁡

"This is the first time there has been any sort of problem whatsoever and [the camps] don't happen once a year - they happen twice a year."

However, Williams doesn't believe the camps should end, and points to Jacinda Ardern's success since attending a camp as a young person.

"We set these up years ago in the hopes of producing another Helen Clark and frankly, we did it!"

LISTEN ABOVE AS MIKE WILLIAMS SPEAKS WITH MIKE HOSKING