Detective Senior Sergeant Leigh Jenkins said about $200,000 in cash, 14 firearms, 844 cannabis plants and 12.3kg of cannabis head was seized in the operation.
A substantial amount of equipment used for cannabis cultivation was also found.
Jenkins said a 59-year-old man has been charged with supplying cannabis, cultivating cannabis, possession of cannabis for supply, and unlawful possession of a firearm.
He is due to reappear in Ashburton District Court on September 9.
He is set to appear in Ashburton District Court on August 19.
"The investigation into this offending is ongoing and police are not ruling out laying further charges as our enquiries continue," Jenkins said.