United Future leader and Associate Minister for Health Peter Dunne has admitted smoking cannabis in his hay days.

He made the confession to New Zealand Herald online readers on a live chat.

Mr Dunne spearheaded the campaign to push a ban on synthetic cannabis through Parliament.

He told readers he smoked cannabis as a student “a couple of times” back in the 1970s.

Despite his past slip-up(s), he told the Herald he had seen many health reports that made him believe “firm measures” were needed to protect the health of the general public.

In total, 43 synthetic cannabis products were removed from shelves this week in a bid to make manufacturers prove they are safe.

"The items are simply being removed from the market while their public safety is assessed. Their ongoing status will then be determined by an independent committee,” Mr Dunne told the NZ Herald.