Criminals are exploiting New Zealander's ambivalence towards the "love drug" Ecstasy to market dangerous new substances to young people looking to party.
Record amounts of the psychoactive drugs known as "bath salts" have been intercepted at the border in the past three years, as the methamphetamine market begins to tail off.
Bath salts are a new drug here, but not overseas, where they have been linked to several disturbingly violent incidents including one man who tried to eat part of another man's face, leaving him hideously disfigured.
They have also been linked to the unsolved murder of Auckland man Lee McMurdo, who was believed to have been dealing the drugs when killed last year.
In releasing its latest drug seizure figures, in Auckland yesterday, Customs officials stressed the growing bath salts trend was not short-term, and it would require a joint government approach to combat it - plus a shift in thinking from the public.
"This is a big problem for New Zealand," Customs drug investigations manager Mark Day said.
"We have a culture that readily whacks tablets. But sooner or later chemical drugs are going to find themselves in the hands of some people and there will be one act that happens and it will change our view overnight."
He said, however, that point might not come until there was an act in the community "so ghastly" that people ceased to tolerate the drugs.
Customs group manager of investigations and response Bill Perry said the dealers marketing bath salts would mix methylone with additives such as baking powder, then colour it and press it into pretty tablets to make it attractive to young people.
"They're tucking on to the coat-tails of the Ecstasy market. There's a definite marketing campaign around it being like a 'love drug'."
Perry said there was very little actual Ecstasy on the streets anymore - instead the pills had been replaced with cheap, "analogue" Class C drugs or what Customs call "Ecstasy mimics".
A single kilogram of bath salt powder has a street value of about $60, 000. The tablets retailed for about $25 to $40 per pill - compared to Ecstasy prices of between $80 and $120 per pill.
The officers stressed that while a Class C drug, bath salts were not harmless. Increasing numbers of people were ending up in hospital after a reaction from the chemicals in the drugs.
"It's got all sorts of drugs in it and that's the danger - we don't know what's in the composition of the powder," Day said.
The difficulty for legislators was staying ahead of the trend to ensure the drug laws kept up with chemists, who would quickly change the molecular make-up of banned substances to get around regulations.
Meanwhile, the amount of methamphetamine and pseudoephedrine seized at the border has declined, leading to a belief the "P" market may be tailing off. Street prices were up, indicating a reduction in the amount of the drug on the street, Customs said.