The amount of cocaine, methamphetamine and ecstasy seized by Customs has soared over the past two years, while seizures of pseudoephedrine-based products sometimes used to manufacture P have dropped.
In 2017, 35kg of MDMA (ecstasy), more than 320kg of methamphetamine, 55kg of cocaine and 4044 pseudoephedrine-based products were stopped at New Zealand's borders.
Four years ago Customs seized 3.8kg of MDMA, 20kg of methamphetamine, 82.2g of cocaine and 10,186 pseudoephedrine-based products.
Police and Customs believed the high prices Kiwis are willing to pay for illicit drugs has contributed to the spike, as transnational organised criminal groups try to smuggle more product into the country because they see New Zealand as a lucrative market.
Detective Superintendent Greg Williams, national manager of the police's organised crime group, said 4-5g of methamphetamine- which a reasonably heavy user might use in a week - had a street value of about $2500 in New Zealand.
He told the Herald on Sunday methamphetamine, MDMA and cocaine were cheap to produce overseas, so gangs were willing to risk having some of it seized.
International criminal groups were also becoming more sophisticated in how they distributed drugs, teaming up with local gangs and interacting directly with New Zealand consumers on the dark web.
According to figures released by the Bloomberg Global Vice Index on Thursday, New Zealand is the second most expensive country in the world to buy items including marijuana, amphetamines, cocaine and opioids as well as cigarettes and alcohol.
A basket made up of a bottle of alcohol, a packet of cigarettes, a gram of amphetamine-type stimulants - like methamphetamine or ecstasy - a gram of cannabis, a gram of cocaine and a gram of opiods would cost Kiwis US$1000, ($1369), the research said.
Williams said the highly addictive qualities of drugs like cocaine and methamphetamine were driving demand.
Organised criminal groups knew this and would often make the drug cheap and available to start with to get people hooked.
"Once those people are addicted, then they are having to find the money to pay for the drug. There's where we get the impact across families and communities," said Williams.
Since February last year, local authorities had identified and dismantled 17 transnational criminal groups operating in New Zealand, Williams said.
Customs' investigations manager Bruce Berry said international criminal groups would manipulate the supply of complete drugs and precursors of methamphetamine to maximise profits.
"We suspected that the influx of foreign workers has opened a market for varying drugs that traditionally aren't strong in New Zealand. But really the driver is the availability in the money side of high prices in New Zealand."
He thinks a "glut" of product in the international drug market was also likely contributing to the number of seizures as international gangs had more product to distribute worldwide.
Berry said there was a drop in seizures of pseudoephedrine-based products because international authorities had tightened controls on these items as they are used in the manufacture of crystal meth.
"We've seen a shift from pseudoephedrine to ephedrine and other types of precursors. That is consistent with international trends and we're working closely with international partners on how to disrupt those supply chains."
However, Ross Bell, executive director of New Zealand Drug Foundation, challenged the view that high retail drug prices in New Zealand was driving Customs' seizures up.
During the last few years Customs had been given more powers and technology used to gather intelligence about drugs had improved, he said. The Government had also allocated more money for law enforcement drug operations.
"I would hope that investment is showing up in increased seizures."
He said it was impossible to know whether an increase in supply was leading to more seizures or if Customs was just becoming more successful in detecting illicit drugs.
Bell attributed the high retail prices of methamphetamine, MDMA and cocaine to New Zealand's distance from the countries where these drugs were being produced.
The level of risk required to smuggle drugs into a country was directly related to retail prices, he said.
Bell believed illicit drugs being expensive was actually a postive thing because high prices put people off.
"We don't want to see that price come down," he told the Herald on Sunday.
Bell added that high retail prices didn't necessarily equate to a market being lucrative for international organised criminal groups.
"Yes, they might be getting top retail dollar here, but the market remains really small compared to the markets of Europe or North America," he said.
Bell described what was happening with methamphetamine as "the balloon effect".
"When you get a balloon and you squeeze one part it's going to pop out somewhere else."
For years Customs and police had cracked down on the supply of precursors like pseudoephedrine and gangs had responded to this by importing the final product instead.
"That's typical of any drug market. When you put pressure on one part of the market the market will respond. That's because you've done nothing to address the demand for the drug. That's what remains a real challenge for New Zealand," said Bell.
His view was that the only way to reduce demand was to invest in treatment for addicts and education about the dangers of severe drug use.