Police have seized 35 firearms and 15,000 rounds of ammunition in a major operation in Auckland last week.
In a statement, Detective Senior Sergeant Mike Williams said the operation was the result of an investigation into unlawful possession of firearms.
Police executed search warrants at three New Lynn properties on Friday, Williams said.
"As a result of our enquiries, a significant cache of firearms, ammunition, and explosives were located from two of the searched addresses."
A 53-year old man has been arrested and faces 29 charges relating to the unlawful possession of firearms and magazines, as well as a charge of possession for supply of cannabis.
Williams said the man held a firearms license but police allege many of the weapons were in his possession illegally.
The man's firearms licence has since been suspended by Te Tari Pūreke, the Firearms Safety Authority, Williams said.
The man has already appeared in Waitākere District Court and is due to appear again in early January.