An operation investigating the importation of methamphetamine into New Zealand has seen the largest ever interception of the illicit drug at our border.

New Zealand Police, with the assistance of Customs, intercepted a shipment of 613 kilograms of methamphetamine arriving through Auckland Airport last Thursday.

This interception has a retail value of more than $245 million.

Commissioner of Police Andrew Coster says the National Organised Crime Group had been investigating a criminal syndicate's alleged involvement in importing controlled Class A drugs into New Zealand.

Investigators, as part of Operation Weirton, made further enquiries into the intercepted shipment over recent days.

Several search warrants were terminated across south Auckland late yesterday.

Six people, aged between 27 and 36, were arrested with some of those having links to the Comanchero Motorcycle Gang.

All are facing serious drugs charges in the Manukau District Court relating to the importation and supply of methamphetamine, along with money laundering offences.

Commissioner Coster says the interception of methamphetamine as part of Operation Weirton is the largest ever at New Zealand's border.

'This seizure of more than half a tonne is a significant result by our National Organised Crime Group to combat the harm methamphetamine causes to our communities.

'Had this shipment been distributed across New Zealand it would have caused immense harm to the vulnerable communities these criminal groups were preying upon.

'Police estimate this seizure would have caused more than half a billion dollars' worth of social harm, according to drug harm index figures.

'Had we not made this seizure, those communities would have continued to suffer, and the individuals involved in this offending would continue to profit from the destruction with no regard for those they have affected.

Customs Group Manager Intelligence, Investigations & Enforcement Dana McDonald says Customs is mandated to protect New Zealand through its role at the border, and a having a partnerships approach is critical to disrupting this type of transnational crime.

'In this instance, our partnership with Police and international agencies has prevented a significant amount of social harm to New Zealand. Customs will continue to work with Police and our international partners to target and dismantle transnational organised criminal groups.

'These organised criminal groups undermine the wellbeing of our communities, with criminal groups profiting by taking advantage of these communities – this seizure has made a significant impact in preventing further community harm.”

Commissioner Coster says Operation Weirton is another example of law enforcement's commitment to disrupting and dismantling organised drug networks in this country.

'I'm incredibly proud of the work our Police staff across the country continue to carry out every day in keeping our communities safe.

'This success highlights the strong partnerships in place between Police, Customs and our international partners in targeting criminal activity at our borders and in the community.

'We appreciate the assistance provided by Customs in this operation, particularly with the exceptional profiling of shipments from high-risk countries which end up resulting in these large interceptions.

'Police remain committed to making New Zealand more resilient to transnational organised crime and we will continue to target those that illegally obtain assets and wealth through the sale of illegal drugs.”

Operation Weirton remains ongoing, and the National Organised Crime Group will continue to make enquiries.

Police cannot rule out identifying further individuals involved and further charges being laid as a result.