Streets were cordoned off for more than two hours in Whangarei on Tuesday while the armed offenders squad searched a man's house for illegal firearms.
The police say the squad was called to an address in Tikipunga at 4 o'clock following reports that a man who didn't have a firearms license, was in possession of weapons.
They say no shots were fired while the house was secured, and cordons were lifted at about seven pm.
The police say a local man, who is 35, has been taken into custody and charges are likely to be laid on Wednesday.
They say a number of addresses are being searched as part of their investigation.