Six remote West Coast gold mines have been targeted by thieves on a crime spree.
The offenders stole gold and tools and reportedly caused hundreds of thousands of dollars of damage.
Police confirmed they are investigating six burglaries at separate mines, which all took place last Thursday night.
Tracy Billingsley, who is a partner at one of the mining sites, said the thieves took half a tonne of gold-bearing material and flipped over a new dump truck.
"As well, the thieves started our 38-tonne digger and smashed everything in its path and that included our trommels [gold wash plants] ... there was just a ton of damage," Billingsley told the Greymouth Star newspaper.