Four men have been charged with arson after explosives were set off in a historic quartz mine causing significant damage.
The Big River Quartz Mine on the West Coast is a category 1 historic place. Photo: DOC
The police say a group of people entered the Big River Quartz Mine between 10 June and 7 July.
The area is a category 1 historic place and the explosion caused significant damage to a 12-metre high structure above the mine shaft.
A film of the offending was shared on social media, prompting enquiries in Reefton and Hokitika.
Last week police executed five search warrants at residential addresses.
Six men were arrested, with four aged between 20 and 53 due to appear in the Greymouth District Court on Wednesday.
Police inquiries are ongoing to try and find other people suspected of being involved.
Anyone who has any information which may assist is asked to contact police on 105 and quote file number 210707/6710.