A number of private houses have been discovered selling synthetic cannabis in Tauranga - confirming predictions the industry is going underground, the Drug Foundation says.
In Tauranga, people using the banned drugs have told Radio New Zealand News about private houses selling synthetic cannabis in the suburbs of Hairini, Merivale, Gate Pa, the lower Kaimai Ranges and Greerton.
Police would not confirm the locations because it could compromise their investigations but said they had some prosecutions under way.
Jacob, 21, who did not want his last name used, went to a Tauranga house and paid $20 for about 2.5 grams of synthetic cannabis.
He said buying the product from a house was cheaper than buying it from the shops but admitted he had no idea what was actually in the small plastic bag he bought.
Tommy Wilson from Te Tuinga Whanau Support Services in Greerton said they were seeing the same clients with the same synthetic cannabis problem.
He said the only difference was that the shop front had moved. "Yeah, five this week, and there'll be five waiting in the wings. We could drive in a car within an hour of here and do all five."
Mr Wilson said having the product available privately had brought a new set of problems for his agency to deal with.
He said it was a "quick, easy, accessible high" and the gateway to illegal drug P. "It's the gateway to the main game," said Mr Wilson.
The Psychoactive Substances Amendment Act came into effect in May 2014. Now, to legally sell synthetic cannabis, a product has to pass a testing regime and be sold with a licence. No companies have so far received a licence.
'It's a recipe for disaster'
The Drug Foundation and other social service agencies had warned that removing all of the products would push them to the black market.
The foundation's director, Ross Bell, said the news that at least five houses in Tauranga were selling the banned products came as no surprise.
He said the Psychoactive Substances Amendment Act, which stopped the products being tested on animals, made it almost impossible for the products to be tested to make sure they were safe.
He said no one wanted to see testing on animals but, until an alternative came, the synthetic cannabis industry would probably stay underground.
Mr Bell said other countries were watching New Zealand to see if the new laws would work - but they hadn't.
"It's wonderful to be a world leader and have this great law sitting on your books but it's kind of embarrassing that the law isn't going to work."
Mr Bell said the technical problems in the law needed to be fixed, but he did not think there was the political appetite to do it.
Dr Tony Farrell is a Tauranga GP with a fellowship in addiction medicine.
He said letting the sale of the drugs go underground was not a good move and regulating their sale would be preferable.
"People who sell drugs illegally aren't always the most honourable of creatures. And people who get into a dependable state can start putting things on tick," he said.
"And if they can't pay, you often see violence and other issues, coercion into certain activities. So I think it's a recipe for disaster."
Associate Health Minister Peter Dunne said the black market activity was the consequence of pernicious people stock piling the drug.
Listen to Peter Dunne
Mr Dunne told Morning Report the legislation did not drive the market underground. "We are in a transition phase and I think we've got to be very careful about assuming that the spread of these drugs is as widespread as it was before the legislation was passed."
Western Bay of Plenty Area Prevention Manager Inspector Karl Wright-St Clair said that when enforcement opportunities arose, they would take action.
"A case from Tauranga is currently before the court with the individual is charged with the illegal supply of psychoactive substances and awaiting sentence.
"Feedback following a recent operation in neighbouring Rotorua also shows that the public do not want the harm caused by psychoactive substances in their communities and are supportive of the work of the police and other agencies."
He said: "If anyone has information about the illegal use of sale of the products, we encourage them to report it to the police."