Police have informed Stuff that in June they seized $6.2 million in various cryptocurrencies and $800,000 in New Zealand currency from a Hamilton-based operator of what they believe is a movie pirate website.

This month, police seized a further $377,000 in New Zealand currency and $472,000 in cryptocurrency from someone they say was an associate of the man.

Detective Senior Sergeant Keith Kay of the Asset Recovery Unit said in a statement that "introducing illicitly-obtained funds into New Zealand constitutes money laundering and police will thoroughly investigate and restrain the assets of those who undertake such activity".

Police were tipped off by the US Inland Revenue Service in 2016.

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The man is thought to have been using international money transfer services including PayPal and Stripe to send money between Vietnam, New Zealand, Canada, and the US.

Assistant Commissioner of the Investigations, Serious and Organised Crime division Richard Chambers, said the operation demonstrated "the capability of our investigators to prevent and respond to cyber-crime and money laundering, which are often unbounded by geography".

The $6.2 million in cryptocurrency is the largest amount of digital coin seized by New Zealand authorities.