Toxic liver-destroying drug methylenedianiline has been detected in a sample of what was thought to be MDMA in Auckland.
High Alert, an early warning system for dangerous drugs, shared the alert to their website on Friday saying the chemical had been linked to "several poisoning cases in Auckland".
Methylenedianiline is a well-known liver toxin listed as a "substance of very high concern" - with all poisoning patients suffering from liver damage.
The substance the patients took was confirmed to contain the toxin following testing by the Institute of Environmental Science and Research.
High Alert "strongly urges" people not to take methylenedianiline, adding it's non-psychoactive and doesn't have any effects of MDMA.
"The concern is that the substance will continue to be sold as MDMA. It is unknown how widespread the circulation of this powder is," High Alert says.
Symptoms the toxin causes include skin irritation, abdominal pain, vomiting, fever, and jaundice. Symptoms usually occur within 24 hours of ingestion but some may not show up for a week.
The substance is difficult to identify from MDMA, as it has a similar brown, crystalised, or powder form.
MDMA users are encouraged to get their drugs tested, and Know Your Stuff is running a drug testing station in Parnell on Sunday providing users with the opportunity to do so for free.
Know Your Stuff, which offers a judgement-free service, says almost one in 10 drug samples are not what the user believed they were and after discovering this 52 percent of people decide not to take the substance.
The discovery of the methylenedianiline follows Prime Minister Jacinda Ardern revealing she wants a plan to allow concert-goers to get their drugs legally tested in an effort to keep people safe.
"I do think people appreciate that it's not about changing the legal framework for those individual drugs. It's about saying there's evidence overseas that regimes like that save lives, and who would we be to turn away from that."
It's currently illegal for a venue to be used for drug consumption which means drug testing cannot be completed on-site.
Know Your Stuff operates in a legal grey area where they supervise a person in possession of illegal substances testing their own drugs - without being in possession of the drug themselves.
Ardern is hopeful drug testing will be available for the upcoming summer festival season.
