Watch police press conference from Detective Inspector Gary Lendrum
Seven people are dead after using synthetic cannabis this month in Auckland, with ambulance staff saying they also see 20 users a day suffering "life-threatening effects" from the illegal drug.
The deaths have prompted the Chief Coroner and police to issue a public warning about synthetic cannabis.
Chief Coroner Judge Deborah Marshall said the seven dead are 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.
"While the police and coronial investigations are still at an early stage, and the final causes of death have yet to be established, the number of cases where synthetic cannabis appear to have been a contributing factor has prompted me to issue this public warning," she said.
Police are releasing CCTV footage that shows a man in the Auckland CBD last year unable to stand after smoking synthetic cannabis.
Detective Inspector Gary Lendrum said today a press conference the synthetic cannabis was better described as a "psychoactive drug" as police "don't really know what is in the product that is being consumed"
Lendrum said the message from police was clear - people should stop using the product and those who are aware of family members using it, should intervene.
"If they can't get them to stop, please seek help. If we don't do something about this further people are going to die."
He said police have been targeting distributors for some time but needed the public's help to continue doing so.
"Please contact us if you are aware of people in your community selling this drug".
Lendrum said synthetic cannabis is an issue right across the country with frontline staff reporting a spike in the number of people under the influence of 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"
Police have had reports of people from the age of 13 right up to 60 years old, taking the drug.
Four of the seven deaths have been "very recent".
When asked about concerns regarding police sharing footage of someone on the drug, Lendrum said there was already footage on social media already for anyone to see.
"What we are trying to do there is focus people's attention, 'this is what's happening in our community, this is what's happening to our family members'."
He said while there have always been deaths associated with drugs in New Zealand, this was a "significant spike"
Lendrum said one of the deceased was in his 60s and another was 44.
It has been suggested that the product is synthetic cannabis, laced with chemicals.
Police seized close to 5kg of synthetic cannabis in Counties Manukau in May at a property connected to gang members.
Lendrum said police are releasing the footage to highlight the effects of synthetic cannabis.
"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 police have searched multiple properties and arrested numerous people across Auckland as they crack down on the drug.
One synthetic cannabis operation in Avondale has resulted in 12 arrests over the past few months.
"It is a dangerous, illegal substance and we will arrest those who are selling this harmful drug and place them before the courts," he said.
Emergency medicine specialist at Wellington Hospital Dr Paul Quigley said a single smoke of synthetic cannabis is 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.
"It appears that it has returned into illicit use particularly into our lower socio-economic groups and those marginalised in society."
Quigley said they have "very few, if any" presentations at the Wellington emergency department.
"However our colleagues at Hutt Valley Hospital report regular attendances by users of synthetic cannabis."
The effects of synthetic cannabis aren't limited to Auckland, with Canterbury DHB emergency department clinical director Dr David Richards saying they see the ill effects of "both synthetic and non-synthetic cannabis on a regular basis".
"Anecdotally, it's been noted there is a small change in the side effect profile of the synthetic drug in some people that could indicate there is a new substance, or new ingredient, around.
"Some people are showing increased agitation and confusion, and a few people have suffered seizures."
Police Minister Paula Bennett said in a statement: "Any death of a young person is incredibly sad."These drugs are insidious. Let the message be that the consequences of 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.
Bennett 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 today 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 also said that 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.
"The fact that you've got backyard manufacturers putting together goodness knows what in a totally unregulated market, supplying in a totally unregulated market to all sorts of people just creates the potential for this sort of tragedy to occur.
"This is precisely what we were trying to stamp out at the time of that legislation.
"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.
"The testing regime is now in place, but it is not functional because the Government banned the use of animal testing to prove whether recreational drugs were low-risk. A non-animal test has not yet developed which can provide robust results about the risk level of a drug."
Dunne said he has urged officials to update him about any alternatives which would allow the testing regime to work.
The Government was also working with other countries on establishing an early warning system for psychoactive substances which might be coming across the border. It is likely to be in place next year.
"Had it been in place, that would have, I think, had some preventative effect in these instances.
"I guess they just tragically underline the risk of the situation we face once we have a totally uncontrolled environment, which we have at the moment."
NZ First police spokesman Ron Mark said the Government was partly to blame because it was sending the wrong message to the public by legalising synthetic drugs.
"We were always going to end up in this sad situation. There is a subtle message that says taking synthetic drugs is OK and we have a problem with that."
Mark said the Government's plan for a regulated market was a "pipe dream" which had failed.The Government should instead be increasing its policing of drug manufacturing and dealing, he said.
"Take these drug dealers off the streets. Put then in jail. Eliminate them. That's clearly not happening."
Mark also said police had failed to completely get rid of synthetic drugs when they were banned in 2014."You can go to any city in the country and buy this stuff. And the Government sits there turning its Nelson's eye."
St John medical director Tony Smith said the service was dealing with "up to seven deaths that appear to be linked to synthetic cannabis".
Smith said up to 20 people a day were showing up at hospitals, mainly in Auckland, with "life-threatening effects".
He said people were losing consciousness, having seizures and in some cases their hearts had stopped. St John "believed" the cases to be related to synthetic cannabis.
Smith said St John was "very concerned regarding the dangers of synthetic cannabis".
"We have seen a spike, particularly in Auckland, over the past month where we're seeing up to 20 [people] a day with some life-threatening effects following synthetic cannabis," Smith said.
Smith said numbers had peaked this week with ambulance officers responding to 23 incidents on Thursday and 20 cases on Wednesday related to synthetic cannabis.
"Patients under the influence of this drug are exhibiting grossly disturbed behaviour, suffering seizures. Most concerning is that the drug appears to be linked to some people's hearts stopping beating and we have had seen seven sudden and unexpected deaths," Smith said.
"If these patients are lucky enough to wake up, they can exhibit abusive, threatening behaviour towards ambulance officers and are very difficult to manage."
"We're dealing with up to seven deaths that appear to be linked to synthetic cannabis. We don't know what this drug actually is; it's just been labelled synthetic cannabis.
Smith said St John didn't know if the product was a specific brand or type of synthetic cannabis, but that police were working to identify that.
Auckland DHB chief medical officer Dr Margaret Wilsher said Auckland City Hospital has a had a rapid increase in people turning up to hospital under the effects of synthetic cannabis.
"We have experienced a dramatic increase in patients coming to our emergency department who have smoked synthetic cannabis, having seen 22 cases and one death over the past five days. This is a very worrying trend in presentations.
"The presentation features are often dramatic, including agitation, psychosis, an increased heart rate, seizures, and sometimes collapse," she said.
"Auckland's emergency departments are currently very full, and every patient makes a difference."
Most of the cases are occurring in central Auckland, and ambulance officers are also seeing incidents across the greater Auckland region.
Patients range in age from teenagers through to middle-aged.
Synthetic cannabis has been referred to as a "zombie drug" after video emerged of users slumped and incoherent.
The New Zealand Parliament banned all legal highs in May 2014 until they could pass a testing regime, reversing interim approval it had given for low-risk products as part of the Psychoactive Substances Act.
A Waitemata DHB spokesman said they didn't have enough information to comment, while a Counties Manukau DHB spokeswoman said it was "too late to speak to a toxicology expert".
What is synthetic cannabis?
Synthetic cannabinoids refer to a growing number of man-made mind-altering chemicals that are either sprayed on dried, shredded plant material so they can be smoked (herbal incense) or sold as liquids to be vaporised and inhaled in e-cigarettes and other devices (liquid incense).
These chemicals are called cannabinoids because they are related to chemicals found in marijuana plants. Because of this similarity, synthetic cannabinoids are sometimes misleadingly called "synthetic marijuana" or "fake weed", and they are often marketed as "safe" legal alternatives to that drug.
In fact, they may affect the brain much more powerfully than marijuana. Their actual effects can be unpredictable and, in some cases, severe or even life-threatening.
Synthetic cannabinoids are included in a group of drugs called "new psychoactive substances" (NPS). They are unregulated, and are newly available on the market, intended to copy the effects of illegal drugs.
Synthetic cannabinoids act on the same brain cell receptors as delta-9-tetrahydrocannabinol (THC), the mind-altering ingredient in marijuana. So far, there have been few scientific studies of the effects of synthetic cannabinoids on the human brain, but researchers know that some of them bind more strongly than marijuana to the cell receptors affected by THC, and may produce much stronger effects. The resulting health effects can be unpredictable.