It has been a record year for drug interceptions at the New Zealand border with customs confiscating more than a tonne of methamphetamine.
Imports for MDMA also sky rocketed, with officers reporting a more than 600-percent increase on last year.
Customs manager of investigations Bruce Berry said New Zealand's figures were part of a concerning international trend.
Large-scale organised crime groups throughout the globe were oversupplying drug markets to drive down prices and secure a monopoly, he said.
"They have no concern for the misery it's causing our lower socio-economic groups in our society. In fact, it's now spreading out right across society."
It was comparable to the situation in Kawerau, Berry said, where the Mongrel Mob had flooded the town with drugs in an attempt to control it.
About 70 percent of drug seizures this year had occurred at the mail centre, where smaller quantities would be smuggled in.
The drugs in those cases could range from Canadian cannabis seeds to deep-web internet orders, which was seen on a regular basis.
It was a raft of huge interceptions, including one involving more than 400kg of meth valued at $235 million, that really shocked Berry.
The meth had been concealed inside 60 electric motors, each holding about eight kilograms of the drug, and shipped into New Zealand.
He said he had never in his 36 years of work in customs expected to see an importation of that size and scale.
"We know that there have been previous importations by this group. We recovered in excess of 510 kilograms all up from our inquiries into that one."
The methods of concealment had also become far more complex, with one shipment from Mexico holding drugs inside hundreds of small plastic stacking pallets.
Smaller scale imports did not always warrant a full-scale investigation, Berry said, but Customs kept a close eye on emerging trends.
"Geo-spatially are they all going to the same area?... are they meeting the same criteria around how they're addressed or packaged? So, we think there's one group behind them."