Police seized illegal sawn-off shotguns, semi-automatic weapons and hundreds of rounds of ammunition in a raid on a house.
Officers said the weapons had a potential for disaster that "does not bear thinking about".
A Tauranga armed offenders squad found a dozen single shot and semi-automatic rifles, long and short
barrelled shotguns and pistols in a raid at a house in Pyes Pa, Bay of Plenty, early on Thursday morning.
Silencers, telescopic sights, 2000 rounds of ammunition and cannabis seeds were also found.
The discovery came days after wheelchair-bound Shayne Sime was shot dead by police after wounding a police officer in Christchurch, and weeks after Napier gunman Jan Molenaar killed police officer Len Snee and injured three others, sparking a three-day standoff.
A 48-year-old man was arrested at the house.
'This was obviously a very, very concerning find," said senior sergeant Dave Archibald of Tauranga South police.
"When someone who doesn't have a [firearms] licence is found in possession of this quantity of firearms and these types of firearms it is a real concern.
"It's against the law to have a pistol and this guy has four so the picture kind of paints itself."
Police national manager of operations Tony McLeod said police did not know how many unlicensed gun owners there were, but they estimated there were between 800,000 and 1.2 million unregistered guns.
