Forensic specialists have released the findings of a two-year study into synthetic drugs - which has found a significant difference in what exact substance is killing Kiwi users in different parts of the country.
And it has identified new types of synthetics on the market.
Crown research institute ESR carried out a two-year project tracking synthetic drugs in New Zealand and found a "clear geographical difference" in substance use.
ESR aims to keep local communities safe and healthy through intelligent science.
"Conversely, fatalities linked to synthetic cannabinoids in the central and southern parts of the country were spread among a range of different substances," she said.
"Over the two years of the project we detected synthetic cannabinoids in 90 deaths referred to Coroner that may be linked to use of these drugs.
"Of those cases, more than 80 per cent were linked to AMB-FUBINACA, recently reclassified with Class A drug status."
Synthetic drugs were originally developed to be a legal alternative to cannabis.
However, on May 8, 2014, following nationwide protests against the drug, it became illegal to sell or use psychoactive substances in New Zealand.
In August this year the Misuse of Drugs Amendment Bill passed its final reading - giving police discretion to take a health-centred approach, rather than prosecuting those in possession of class A drugs.
It also classifies the main substances of synthetic drugs - AMB-FUBINACA and 5F-ADB - as Class A drugs and enabled temporary drug class orders to be issued for emerging substances.
Dr McCarthy said the research detected a range of synthetic drugs during the two-year survey, with different patterns of use potentially the result of the illicit drug supply chain.
The data gathered was the result of working closely with New Zealand Police, Customs and the Ministry of Health.
"Our data was used to inform and assist health and enforcement agencies to tackle the harm being caused by these dangerous drugs," McCarthy said.
ESR's surveillance of synthetic drugs is part of a worldwide response to the synthetic substance crisis.
The agency also contributes to the United Nations Office on Drugs and Crime and receives regular updates on new substances coming into the market.
Three ESR staff have recently returned from a forensic toxicology conference in the UK, where recent trends in the constantly changing synthetic substances market were being observed and shared.
"Being able to share our data within New Zealand and internationally is helping us predict, prevent and protect New Zealand communities," said McCarthy.