Criminal syndicates in China have devised a new way to get methamphetamine into the country, by making the drug undetectable.
Police and Customs have made their first ever seizure of what's called "t-boc", a chemical agent used to disguise other compounds.
Described as dishwashing liquid, the chemical turned up in a shipping container from Hong Kong. The police say the method of smuggling is something they haven't seen before.
"What's unique about it is that when it arrives in New Zealand, it isn't actually methamphetamine. At that point it's not actually a controlled substance... so that's the challenge we have," Detective Superintendent Dave Lynch says.
T-boc masks the drug, then through another chemical process the masking agent is broken down and remanufactured into meth.
"It does appear to be a fairly new method, and information we've collected on this job would indicate it's the first time that it's come into New Zealand in this form," Supt Lynch says.
University of Auckland's deputy director of forensic science, Gordon Miskelly, says t-boc is known as a "protector" chemical.
He says the authorities will need to adapt screening methods to make sure they pick up the drug in any future consignments.
"Now that they've seen this once, they'll know to look for it."
The managing director of drug education group Methcon, Dale Kirk, says the new discovery doesn't come as a surprise.
"The key thing for me is that it just shows the lengths that dealers will go to getting methamphetamine into New Zealand," he says.
Mr Kirk says demand for the drug remains huge in New Zealand.
"We love the stuff. We have a massive demand for the product in New Zealand. We also pay a premium for methamphetamine compared to countries like the States," he says.
"We pay probably around 10 times as much per gram in New Zealand compared to America for methamphetamine."
He says there needs to be greater focus on education to reduce demand for the drug, and more funding is required for rehabilitative services.
Finding the masking drug t-boc is relatively rare, even when looking at other countries around the world.
Police in Australia found the compound just once last year. On that occasion, it was being used to hide another popular drug, MDMA.
After being tipped off to the t-boc haul from drug agency partners in China, police in New Zealand searched several homes and commercial premises in Lynfield, Waitakere, Newmarket, Epsom, Avondale and New Lynn.
Police found drugs, cash and equipment used to make meth at some of the addresses.
The searches resulted in the arrest of four men, all of whom have been charged with a variety of possession and manufacturing charges.