The National Organised Crime Group and the Firearms Safety Authority began investigating after residents awoke to shots being fired near a house in rural Cheviot in April.
Detective Inspector Albie Alexander said two men without firearms licences later pleaded guilty to unlawfully possessing firearms and discharging a firearm near a dwelling.
"Of the six firearms located in their possession, four were registered to other people. Thanks to the Firearms Registry we were able to trace the licence holders who allegedly diverted their firearms," he said.
"The investigation revealed alleged attempts to subsequently conceal the offending by providing misleading information about the true ownership of the firearms."
Police executed search warrants last month and seized 31 firearms as a result.
Six further people were now facing charges including supplying a firearm to an unlicensed person and knowingly providing false or misleading information to the police for the registry, Alexander said.
Two men, aged 22 and 73, and two women, aged 52 and 73, from Kaikōura were due to reappear in the Kaikōura District Court next month.
Two Hurunui men, aged 47 and 38, would appear in the Christchurch District Court this month.
Firearms Safety Authority director Angela Brazier said illegal hunting was a serious public safety concern in rural communities.
"The Firearms Registry links firearms to licence holders, improves traceability, and supports frontline police. The majority of licence holders have no trouble complying with their registry obligations and know the rules about keeping firearms out of the hands of unlicensed people who may go on to commit offences," she said.
"To date more than 110,000 active individual licence holders have listed their details in the Firearms Registry, more than 49 percent of all active licence holders. They have registered more than 538,000 firearms.
"Licence holders have until August 2028 to update the registry unless they have an activating circumstance before that date, such as buying a firearm or ammunition."
