More than 300 cannabis plants, worth thousands of dollars, were reportedly found by Northland police at a commercial property in Whangārei.
Detective Senior Sergeant Aaron Crawford, of Northland CIB, said specialist police groups - including officers from the National Organised Crime Group - carried out a search warrant at the address on Tuesday.
There, they discovered the haul of cannabis plants.
“A large-scale enterprise like this can illegally generate millions of dollars if undetected,” Crawford said.
Police arrested two men, aged 36 and 38, found at the address.