More than 400kg of methamphetamine was seized by New Zealand Customs in 2016, which the agency says was 20 times the amount grabbed three years earlier.
It's on top of 1.1 tonnes of meth ingredients Customs also seized last year, which could have made 809kg of the drug.
The interception of meth was at a record high in 2016. Investigations manager Maurice O'Brien says it's down to criminals trying harder and a glut in the global market.
"New Zealand's meth and MDMA prices are much higher compared to many overseas countries, which makes smuggling a lucrative business," he said.
The rise in drugs coming in from internet orders is rising, just like that of regular e-commerce purchases," Customs cargo operations manager Bruce Berry said.
"New Zealanders are looking for price, choice and opportunities... with illicit substances as well."
Around 70 percent of intercepted drugs are in small quantities through the mail centre.
"We're seeing an increased variety of drugs, and their precursors, mimics, synthetics... You name it it's coming through there.
"The end user should be aware: You don't know what you're dealing with."
Mr O'Brien says the police are working closely with international agencies to identify sellers off shore.
"We call this upstream disruption. We think this is the most effective way to stop them."
- 2016: 413kg of meth
- 2015: 283kg
- 2014: 82kg
- 2013: 21kg.