However, despite being prevalent in the community last year, AMB-Fubinaca appeared to temporarily disappear from the New Zealand black market this year with the last previous detection made in November 2019.
That was what made the three recent detections extremely alarming, High Alert said.
"The unusually wide geographic range of these most recent detections causes concern there could be a wider re-emergence of AMB-Fubinaca in the community," it said.
"This is particularly concerning as AMB-Fubinaca has been one of the most lethal illicit substances in New Zealand in recent years."
In September last year, Chief Coroner Deborah Marshall's coronial inquiry revealed that at least 75 people across the country had died after taking synthetic drugs between June 2017 to 2019.
AMB-Fubinaca was involved in 80 per cent of those deaths.
It also became infamous for inducing zombie-like behaviour, and fuelling an outbreak in New York in 2016 that gained it worldwide notoriety.
High Alert said the immediate effects of AMB-Fubinaca could include:
• Fast or irregular heartbeat
• High blood pressure
• Nausea, or vomiting
• Tremors
• Sedation, drowsiness
• Slowed reaction times
• Confusion, loss of touch with reality
• Paranoia, anxiety and panic attacks
• Loss of consciousness
Other serious adverse effects are reported to include aggression, difficulty breathing, harmful thoughts, suicidal feelings, hallucinations, psychotic episodes, seizures, and death.
Detective Inspector Blair Macdonald, manager of the National Drug Intelligence Bureau, said police had been making steadily fewer seizures of the drug since 2017/2018.
This was due to authorities targeting the import and sale of it, greater awareness of its dangers and laws banning it both in New Zealand and overseas, he said.
New laws in August last year, designated AMB-Fubinaca and 5F-ADB as Class 'A' controlled drugs.
"This elevated these two substances into the same category as methamphetamine, heroin and cocaine, with a maximum sentence of life imprisonment for the sale, supply and manufacture of these drugs," Macdonald said.
Moves by the Chinese government to restrict the manufacture of the drugs also had an impact in reducing their prevalence.
However, there were still 37 hospitalisations related to "synthetic cannabinoids" in 2019, Macdonald said.
"The threat of another synthetic cannabinoid outbreak is very real and in part led to the development of New Zealand's first drug early warning system, High Alert," he said.
"Highalert.org.nz provides the public with alerts and notifications when dangerous substances are identified."
Associate professor Chris Wilkins, a drug researcher from Massey University, also said AMB-Fubinaca was extremely dangerous.
"Its risk in synthetic cannabinoid products is exacerbated by unregulated black market production and manufacturers with limited or no expertise in chemistry," he said.
He said greater research was needed to understand why some Kiwis used synthetic cannabinoids.
"It is also worth noting that most people who use synthetic cannabis have reported they prefer to use natural cannabis, and consequently greater legal access to cannabis could be considered," Wilkins said.
"Countries with more liberal cannabis laws are less likely to report synthetic cannabinoid use and related deaths."
Doug Sellman, professor of Psychiatry and Addiction Medicine at the University of Otago, also said that one of the downsides of banning natural cannabis was the emergence of highly potent and dangerous synthetic alternatives.
These were often deliberately made into highly potent varieties that meant smaller quantities could be more easily hidden and transported illegally.
"This phenomenon is exactly what happened in the United States during prohibition of alcohol (1920-1933) when very high potency alcohol produced illegally at the time for ease of transport and sale was associated with a concerning number of deaths," Sellman said.
"This was a factor in the decision by the US government to regulate alcohol rather than continue prohibition."
High Alert said there were many ways the manufacture of illegal synthetic drugs could go wrong.
"The application of synthetic cannabinoid powder can lead to varying concentrations, even within the same batch, worsening the already potent effects of AMB-Fubinaca and further increasing the likelihood of overdoses, and possibly death," it said.
Synthetic cannabinoids were also not tested in the way medicinal drugs were tested, and were not proven to be safe.
"The effects experienced can also be exacerbated by other drugs or alcohol taken, a person's mental health, or the presence of underlying medical conditions."
