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.
Inspector Glen Baldwin said it's a good feeling to "get another dangerous weapon off the streets".
"It's also a relief to be able to tell the vehicle owners, their vehicle has been recovered," he said.
Police also thanked members of the public for reporting the suspicious behaviour.
"The community's information can often be beneficial to an investigation, and we encourage people to report any suspicious behaviour," police said.
This can be done by either contacting 105 after an event or by calling 111 if it's happening now.
You can also contact Crime Stoppers anonymously on 0800 555 111.