Police Commissioner Andrew Coster says they are speaking to "two people of interest" after the fatal shooting of an officer in West Auckland today.
In a news conference held late this afternoon, Coster said Auckland police would remain armed for the time being, until they were "satisfied the right people are in custody".
He said a firearm had been recovered.
Two officers were shot, one fatally, after after the incident that happened at around 10.30am on Reynella Drive in Massey.
The second officer who was shot is in a stable condition in hospital
Coster said multiple shots from a long barrelled firearm were fired at the officers after they approached a vehicle that had crashed after they had tried to pull it over.
He said a "large number of police from across Tamaki Makaurau" as well as the Armed Offenders Squad were involved in the hunt for the perpetrators.
"Our priority is to hold this offender to account," Coster said.
A member of the public was also hit by a vehicle after police performed the traffic stop and suffered minor injuries.
Today's death is the first police fatality in the line of duty since 2009.
See how the day developed with RNZ's live blog: