Two people have appeared in court charged with supplying MDMA after police believe a 20-year-old died from taking the drug.
Police have issued a warning after his death and two other incidents in Queenstown over the weekend.
MDMA is one of the most common party drugs in New Zealand.
What's uncommon is a fatal dose, but that's what police believe occurred in Christchurch over the weekend when a man died after a suspected MDMA overdose.
A man and a woman in their 30s appeared in court on Thursday charged with possession for supply of a Class B drug and police have said they can't rule out further changes.
The man received name suppression which police opposed, saying the public should know his name as he may have allegedly supplied MDMA to other people, who should be aware of this case.
Police said they're also aware of two people in Queenstown who recently had seizures after taking MDMA.
"Enormously upset. We do not need this sort of thing in this district, for those pedalling this rubbish - please leave us," Queenstown Mayor Jim Boult said.
But the Drug Foundation is warning against rushing to conclusions about dodgy drugs circulating in the community and said it's unusual for police to comment on an incident without a toxicology report.
They said deaths from pure MDMA are extremely rare.
"Our advice is for people to always get their drugs checked if they can. One in three that we've checked so far this year has been different to what people thought they were taking," NZ Drug Foundation spokesperson Hayden Eastmond-Mein said.
Some of those drugs are mixed with another substance and many are an entirely different drug.
Police said they partly issued a warning because of a three-day music festival underway at the moment in Queenstown where they know MDMA will be around.
"The best drug is no drug but equally I'm not so naive to think people won't take drugs. What my suggestion is you know what you're putting in your body before you put it there," Boult said.
The Drug Foundation is also setting up an extra testing clinic in Christchurch this weekend to alleviate any concerns.
The message is: If you're going to take it, test it.
