Two men, aged 72 and 63, have been arrested and $5 million in assets have been seized following a major operation in the Tasman district.
Police carried out a covert investigation over several months into the commercial cultivation and widespread supply of cannabis throughout the West Coast and Canterbury, police said in a statement.
Police from around the Tasman district yesterday executed a search warrant at a large rural property in Kaniere, where they found a large underground bunker with a sophisticated cannabis growing operation. A large number of firearms have also been seized.
Police are expected to remain at the scene for a number of days.
On September 9, a 72-year-old Ngahere man was arrested after a search warrant was carried out at his address. The man has been charged with possession for supply of cannabis and is due to appear in Christchurch District Court on September 30.
A 63-year-old man has also been arrested and charged with cultivating cannabis, as well as selling cannabis. He is due to appear in Greymouth District Court today.
Assets estimated to be worth $5 million have been seized by the Southern Asset Recovery Unit.
West Coast area commander inspector Jacqui Corner said information and tip-offs from members of the public have been "instrumental in police being able to prosecute these offenders and take their assets".
"With the scale and seriousness of offending police needed to carefully consider and thoroughly investigate the offending of these groups as well as their assets and put them out of business for good.
"Our investigation team has spent months working to dismantle this drug supply, and in doing so have prevented significant harm reaching our communities," Ms Corner said.
"Drug use is a driver of numerous other crimes so operations of this nature will continue to be a priority for Tasman District Police."
Anyone with information on drug-related offending has been urged to contact police, or anonymously through Crimestoppers on 0800 555 111.