Police have warned the public that more people are going to die if something isn't done to put a stop to synthetic cannabis - a drug that has killed seven people in Auckland this month.

The sudden spike in deaths, including a man in his 60s and a 44-year-old, has prompted the Chief Coroner and police to issue a public warning about the life-threatening effects of the illegal drug.

Chief Coroner Judge Deborah Marshall said the seven dead were believed to have used synthetic cannabis recently or were found with it on them.

"I've also been advised by St John that there have been a significant number of non-fatal cases where people have been hospitalised after using the drug, which is known to cause potentially fatal seizures," Marshall said.


St John medical director Tony Smith said up to 20 people a day were showing up at hospitals, mainly in Auckland, with "life-threatening effects" after smoking the drug.

He said numbers have peaked this week with ambulance officers responding to 23 such incidents on Thursday and 20 cases on Wednesday.

At a press conference yesterday, Detective Inspector Gary Lendrum said the message from police was clear - people should stop using synthetic cannabis or intervene if they know someone taking the drug.

"If we don't do something about this, further people are going to die.

"It is a dangerous, illegal substance and we will arrest those who are selling this harmful drug and place them before the courts."

Lendrum said synthetic cannabis is an issue right across the country with frontline staff reporting an increase in the number of people on the drug.

"They are coming across people that are acting like zombies. That are vomiting, lying on the street unconscious, that are stripping off in public."

Canterbury DHB emergency department clinical director Dr David Richards said they also saw the ill effects of "both synthetic and non-synthetic cannabis on a regular basis".

The spate prompted police to release CCTV footage that shows a man in the Auckland CBD last year unable to stand after smoking synthetic cannabis.


Lendrum hoped this would highlight the effects the drug has, and the significant harm it causes in communities.

"We have grave concerns as users don't know what poisonous chemicals they are potentially putting into their bodies when they're smoking this drug," he said.

Lendrum said there had been suggestions that the drug was synthetic cannabis laced with chemicals.

Emergency medicine specialist at Wellington Hospital Dr Paul Quigley said a single smoke of synthetic cannabis was the equivalent of 15 marijuana joints.

"Synthetic cannabis is one of the more dangerous products around and is responsible for some immediate health harms.

"It is known that there is a significant supply available through the black market and in particular the organised gangs. Much of this is supply that was legal, then stockpiled when it became illegal," he said.

Police Minister Paula Bennett said in a statement: "These drugs are insidious. Let the message be that the consequences of these drugs can be incredibly tragic."

In March, Bennett was challenged by NZ First on whether she was doing anything to combat synthetic cannabis, in particular one drug called Spice.

She said at the time that there was no evidence of any increase in supply or demand for that specific drug. She also said that the use of all synthetic drugs, and harm related to them, had dropped substantially since they were banned in 2014 while a testing regime was set up.

Asked yesterday whether the situation remained the same, Bennett said she wanted to seek advice before commenting.

Associate Health Minister Peter Dunne said he was "desperately concerned" that illegal, synthetic drugs were leading to deaths.

He said he warned of the consequences of having an unregulated market when synthetic drugs were banned in 2014 until they could pass a rigorous testing regime.

"I warned at the time ... that this would create a black market that would be far more dangerous than a regulated market. And sadly, that's what it's proved to be."

While police have been targeting distributors - leading to 12 arrests in Avondale and 5kg of the drug being seized from a Counties Manukau property connected to gang members in May - they have not been able to stem the supply.