More than a dozen butane cans were found in a Christchurch park where a 17-year-old girl died after "huffing" the gas with friends, police say.
And an expert is warning the risk of a fatal butane overdose is nearly has bad as that of heroin as authorities look to control the apparently increasing number of teenagers inhaling the gas.
Sixteen cans were found in Hansons Reserve in Upper Riccarton on Saturday, where 17-year-old Poihaere Eru had been huffing with two friends aged 14 and 16, The Press reports.
Detective Sergeant Craig Farrant says the young women are believed to have bought the butane at a nearby shop.
Det Sgt Farrant said shop owners had a moral obligation to refuse to sell butane to teenagers who were clearly not buying it to go camping.
"We secure spray paint, why can't we secure butane? Because it's killing our kids."
National Addiction Centre director Doug Sellman says many young people underestimate the dangers of things such as butane, which are "not far away from heroin in terms of the risk of overdose".
Solvents caused users to lose inhibitions but also had a "depressive, anaesthetic impact" on the brain, quickly making users feel tired, he told The Press.
They poisoned the respiratory system and could increase heart rate. A surge of adrenaline could cause that beating to become irregular and stop the heart, Professor Sellman said.
Chief coroner Neil Maclean said last month he would look at the issue of huffing after admitting he was surprised that since 2001 there had been 30 deaths attributed to sniffing gas.
In May, a 12-year-old boy died after huffing in a Christchurch carpark.