Five men in Australia were arrested along with a 53-year-old man from Blockhouse Bay, Auckland.
The Organised and Financial Crime Agency of New Zealand has been working closely with the Joint Organised Crime Task Force in Australia over the past five months to bring the investigation to a conclusion.
New Zealand police Assistant Commissioner Malcolm Burgess said it was fantastic to see a number of law enforcement agencies work so closely together on a major international syndicate.
"The partnership between all the agencies involved and the co-operation and intelligence shared has led to these significant arrests in both countries and the seizure of large quantities of drugs," Mr Burgess said.
It is expected that those arrested will face charges relating to trafficking a large commercial quantity of heroin.