The deaths of two people in Christchurch in the past fortnight are believed to be a result of synthetic cannabis use.
Nineteen people have been affected by synthetic cannabis toxicity over the past two weeks in the city, according to Canterbury and West Coast District Health Boards.
Two of those people remain in intensive care and others were admitted to hospital wards.
St John Ambulance has told 1 NEWS that it's attended two deaths in the past two weeks that it suspects are a result of synthetic drugs.
St John also says there has also been "incidents of violence and crew abuse" towards ambulance officers.
Police Minister Stuart Nash told 1 NEWS during a press conference on today that a Cabinet paper is currently being written on the crisis and should be presented to Cabinet in the next couple of weeks.
One solution, he said, might be to increase penalties for the synthetic cannabis so police would have greater power to go after "those who are putting this misery into our communities".
But in the meantime, he pleaded with drug users to "just don't go there" with synthetic cannabis.
"This stuff's killing people," he said. "This isn't just play. This is life and death."
While Christchurch is the city currently dealing with a spate of overdoses, it's a nationwide problem, he added.
"What is happening at the moment is about two substances per week are entering our country that we don't know what they are," he said. "(It's) really hard to test - there's over 600 substances that have been identified.
"So you just don't know what's in them. It's hit Christchurch now, it may be Auckland tomorrow. It could be Tauranga the day after. You just don't know. But this is obviously a very bad batch.
"We really need to do something about it, and we are - believe me."
Megan Woods, who was also in attendance at the press conference, said she knows of at least one person in her own Wigram electorate who has died due to synthetic cannabis overdose in recent weeks.
"It's something we all need to be concerned about," she echoed.