A synthetic drug known as "coma in a bottle" has become more common in the Western Bay of Plenty.
The disclosure comes after Waikato police this week uncovered a laboratory in Huntly producing the drug gamma-butyrolactone (GBL) - possibly the country's first such manufacturing operation.
Four Waikato men have appeared in court on charges relating to the manufacture of the drug, considered a potential date-rape drug.
The liquid chemical was originally produced as a paint stripper and rust remover before being introduced to the party scene, where its effects in small quantities have been likened to the high from ecstasy.
In higher doses, however, GBL has been used as a date-rape drug, causing those who drink the chemical to experience blackouts or become sleepy and disorientated.
Detective Sergeant Alan Kingsbury, of the Tauranga CIB, said the drug had become more prevalent on the local market.
"We are tending to find that more frequently than we were. I guess if you're going to talk about trends, there's probably a trend towards designer-type drugs, synthetic drugs.
We've seized GBL. It was through an investigation into methamphetamine manufacture. I'd say it's more common now than what it [ever] was," he said.
Tauranga detectives have uncovered a number of drug growing and manufacturing operations this year. Mr Kingsbury said he was not able to divulge the details or numbers of operations, as some remained before the courts.
But he said the numbers were probably similar to last year, with methamphetamine and cannabis production still the largest illicit industries.
"I'd say they're probably our two most prevalent drugs. There still seems to be plenty of methamphetamine available. [And] the outdoor [cannabis] growing season is coming to an end but we're seeing... significantly more indoor operations than we were in previous years," he said.