Detective Senior Sergeant Simon Taylor said police had conducted search warrants in rural south Auckland this week, including in Āwhitu, Runciman and Glenbrook.
They resulted in nine arrests so far.
Taylor said the operation was using the sites as "market gardens".
"We believe the set-up, particularly in Āwhitu, is likely one of the largest we have come across within the Counties Manukau Police district," he said.
"This enforcement action has caused a considerable dent and there is no doubt this will have an impact on organised crime as a result."
Taylor said such operations were a large source of income for gangs and organised crime groups.
Police would continue to target them and shut the down.
"We will continue to target such operations given they are funding organised criminal groups' operations, which in turn means harm continues to be imposed on our communities."
In Āwhitu, police said more than two tonnes of cannabis plants at varying maturity levels were located alone.
More than 5450 were destroyed from all three locations.
Four Vietnamese nationals were arrested at the Āwhitu site, and a further five Vietnamese nationals were arrested at Glenbrook.
The men are between the ages of 29 and 40, and six of them are facing charges of cultivating cannabis in Pukekohe District Court.
Police were working alongside Immigration New Zealand with regard to the remaining three.
