A customs officer at New Zealand's biggest airport says it is not just the amount of drugs coming across the borders that is surprising, but the fact that smugglers are not really bothering to conceal it.

The trickle of drugs into the country has become a flood, fed by New Zealanders' appetite for them and willingness to pay.

Between January and May this year Customs officers nationwide seized more than 1600kgs of methamphetamine, cocaine and MDMA.

About a third of that comes through Auckland Airport - it has seized 542kg of methamphetamine and cocaine so far this year.

Customs manager Paul Williams said they're dealing with an increasing number of smuggling attempts, and some of the culprits do not even try to hide it.

"The biggest shift that we've seen is no concealment whatsoever. So we're seeing criminal groups using couriers and you open up the bag and the drugs are sitting there." 

Williams puts the change down to criminals becoming more confident.

"It's a confidence they have, with respect to what they're doing and I expect like any business they perhaps operate at a level of understanding of what type of wastage or what type of level of drugs they may lose with respects to their efforts."

When Williams started out in the sector, a little over two decades ago, drug trafficking was an occasional event, and when it happened the substances were meticulously concealed. But nowadays drugs were found in mail or cargo every day. On just one flight there was a haul of 101 kg.

Customs manager at Auckland Airport, Paul Williams. Photo / Customs NZ

Tracking and uncovering the drugs involved casting a broad net.

"It's not just an officer in a booth, we may have a dog operating... we work really closely with international partners around trends, observations, their own experiences and that helps us look at people in advance through the data the airlines have," Williams said.

A large amount of the illicit drug market comes out of parts of South America and Asia, but Williams said that doesn't mean they only focus on people and luggage coming from those places.

"The key thing to remember is that for New Zealand, we receive multiple flights and multiple vessels from a host of different trade routes and passenger routes... and so criminal groups will always look to try to hide where things are coming from." 

The United Nations Office on Drugs and Crime said organised criminal networks were driving the illicit drug trade, with devastating consequences for people and communities around the world.

It said stopping drug trafficking required long-term co-ordinated action to address supply and demand, and to prevent organised criminal groups from exploiting vulnerabilities.

Williams said there was significant investment in offshore operations because best case scenario was catching the drugs before they even get here.

"It's a real win for New Zealand because, just purely from a fiscal perspective, you don't have a court process, you don't have that lead in time to the court process, you don't have drugs that you have to store and then eventually dispose of.

"You don't run the risk of those drugs actually entering society and having all the actual harm that comes from the consumption from those drugs." 

Williams said the nature of drug trafficking has changed a lot over the years, so reflecting and learning from past cases is essential.

"We've done a lot in the export space... to help and protect the primary exporters of New Zealand, helping them secure their supply chain a bit more and then they get trade-offs through the Authorised Economic Operator programme... faster access to market essentially.

"We work really closely with DHL, FedEx, a host of other facilitators of imported goods and we look to educate them on what it is that we see at the border and we talk to them about exploitation, we talk to them about vulnerabilities within the supply chain.

"The more that they understand how the supply chain works and where the vulnerabilities are the more they are attuned to what's going on and that then results in them talking to us and they can often come to us and say 'we think we've got an issue here,' and we will go in and we'll help them."

-RNZ