Addicts' family members are reporting synthetic cannabis is more dangerous than ever, after moving from dairy shelves to Facebook groups.
The substance was banned in New Zealand in 2014.
In a recent report, a Coroner ruled mental health patient Mark Norman died in 2018 after using a variation of synthetic cannabis known as 5F-ADB, which has also been linked to a string of other deaths.
Today Christchurch Newstalk ZB host Chris Lynch spoke to callers whose family members had also died, or were still hooked on the substance.
Jenny's 44-year-old son, who suffered from schizophrenia, died in 2019. She said despite a police investigation into who supplied him with the drugs, no one was charged.
"The police told us at the time, someone was responsible for the death, and they would prove that. We're still waiting for that proof, and there's still people dying, because of a drug that our Government brought into this country."
Jenny said the day after her son died, the person who sold it to him phoned her daughter asking for proof he was dead, because he owed him $50.
"People deliberately give a drug to others knowing it has the potential to take their life, that is manslaughter, that is murder."
Ben, whose brother is still using after becoming hooked at the age of 13 when the drug was still legal, said he traced the source to a 55-year-old woman.
He said it peaked at 2019 as a legal drug but now it's being made in backyards and no one knows what it is.
"There's no recipe in regards to how it's made, no one knows what's in it, they're just putting anything in it, so people feel like they're on the original drug."
Ben said they've tried everything to help his brother including a stint at drug clinic Odyssey House.
"We've tried isolating him so he can go nuts in a room and once he withdraws it sorts, we've tried mental health counselling and doctors, we've been into hospital multiple times with almost cardiac arrest."
ZB caller Hannah told Lynch her mother swapped out her cannabis for synthetics only last year and suffered a manic episode.
"Her whole world turned upside down, she lost her kids, I don't really talk to her anymore.
"I wanted her to be healthy and safe. When you're under the influence there's no rational thinking, you'll do whatever you can to get your next hit."
These callers have told Newstalk ZB they know where the drugs are coming from including Facebook groups, a dairy and residential addresses still selling.
In a statement, Police said their continued focus is to hold those to account who are manufacturing and supplying the community with drugs.
It said Police are also looking for opportunities to help those impacted by synthetic drug use, such as referrals to the relevant agencies to get people help with drug addiction.
• Police are urging families and friends of those using synthetic drugs to do what they can to help them whether that be taking them to their local GP or contacting the Alcohol Drug Helpline on 0800 787 797