Mt Albert residents keeping an watch on their suspicious neighbour have helped police seize a military-style firearm and an $80,000 stolen car.
Police said the neighbour's "sharp eyes" led Avondale's Tactical Crime Unit to swoop on the Mt Albert home earlier this week and execute a search warrant.
There they seized "a military-style semi-automatic and a large cache of ammunition".
They also recovered a stolen vehicle that had had its number plates changed, police said.
A 35-year-old woman is due to appear in the Auckland District Court on a raft of charges including receiving, unlawful possession of a firearm and unlawful possession of ammunition.