A large-scale investigation was launched yesterday after the man brought the car to the Counties Manukau station about 1.10pm and approached the front counter, a police spokesperson said.
The woman was found dead in the vehicle a short time later, authorities said.
Police had said prior to the man’s arrest that he had been helping with their inquiries into the incident.
An entire Māngere Bridge property was cordoned off yesterday evening, with emergency tape and a white forensic tent set up in the front yard.
Police said a scene examination will continue into the weekend and residents should expect an ongoing police presence “over the next few days”.