Police say the speed of a police car involved in a fatal collision with a four-wheel-drive in South Auckland will be revealed as part of a full investigation.
A 40-year-old woman in the vehicle died and the man who was driving is in a serious but stable condition following the crash on Ormiston Road in Otara about 9am on Wednesday.
A police officer has minor injuries.
Counties Manukau District Commander John Tims says the sergeant was travelling with the siren on and lights flashing on the way to a property break-in.
"As you can appreciate, the police officer is distressed and shocked. We will support the police officer and his family and he will be taking some time off to recover from the accident."
Mr Tims says an independent investigator from another region will be brought in to investigate the crash.
Bystander Sosefo Helu says he heard a loud bang when the vehicles collided and rushed outside to see what had happened.
Mr Helu says the woman's vehicle was turning into the driveway of the Otara Tongan Methodist Church when it was hit.
Three investigations are under way into the crash.
Police Association president Greg O'Connor admits that speeding to an incident can make it hard for officers to react to hazards on the road.
Mr O'Connor told Radio New Zealand's Checkpoint programme on Wednesday that driving at high speeds to police callouts can be dangerous, but the risks are always balanced with the need to get there quickly.