A homeless man on Auckland's Karangahape Road who says he fell unconscious after one puff of synthetic cannabis is warning people not to buy the drug on the street.
Synthetic cannabis, or "sinnies" as it's known on the streets, has now been linked to nine deaths in the past month.
The homeless man told TVNZ1's Seven Sharp he's tried a lot of drugs in his life, including LSD, mushrooms, and synthetic cannabis.
"And all I can says is when I had one toke on it, one puff, I fell into an unconsciousness that lasted, I can't estimate, but I'd say about 20 seconds," he said.
"And I woke up and I felt like I'd been unconscious for hours. It's a strong drug, synthetic, stronger than marijuana. If you're buying it off the street, don't. Don't buy it off the street."
A bouncer outside a K Road nightclub said when he spoke to people about the issue he was surprised that a lot of clientele carry synthetic cannabis.
"I'd say 50 per cent of the crowd tonight would have it in their bags or their wallets," he said.
A young man on K Road said it took only one use of synthetic cannabis by a friend to "mess round with his brain" and the drug has ruined his life.
New Zealand Drug Foundation executive director Ross Bell said people are "buying bags of who knows what", whereas six months ago synthetic cannabis containing a different chemical wasn't causing problems.
Mr Bell said police and the coroner have chosen not to release test results from some of the current synthetic cannabis products.
Associate Health Minister Peter Dunne would not comment before he meets with the chief coroner today.
Mr Bell said the nine deaths are as a consequence of a Government policy choice a few years ago to leave drug control in the hands of the black market, rather than regulate the sale of some lower risk substances.