A large police investigation is continuing on the West Coast of the South Island and in other parts of the country into what police say say is a multimillion-dollar crime ring.
At least one large dairy farm is being searched, along with other properties in the Westport, Cape Foulwind and Denniston areas.
Detective Inspector John Winter said alleged large scale electricity theft has been uncovered as part of a hydroponic cannabis growing operation.
He said police from all three South Island districts are involved in Operation Marvel, targetting both indoor and outdoor cannabis growing.
Eight people appeared at a special sitting of the Westport District Court on Monday on cannabis cultivation and supply charges.
More people were due to appear in court on Tuesday in Nelson, Christchurch and Wellington.
Police arrested a further two people on Tuesday.