The woman, aged 50, died at the scene.
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Acting detective Senior Sergeant Mark Dalzell said police have spoken to around 25 people and would like to talk to any other witnesses who saw the incident or the white Nissan Fuga.
Police allege Takimoana was driving the vehicle at the time of the incident.
The pair were partners who had been together about six years, Dalzell said.
"There had been a domestic dispute immediately prior to this event," he said.
"We're still looking for anyone that may have seen anything."
The woman's family have been notified of her death.
There were several police cars at the scene on Thursday, including crash investigators and detectives knocking on doors questioning locals.
The owner of the Ohaeawai Hotel, which is located at the junction, said he saw the flashing lights of emergency services during the night and noticed the road was closed.
"By the time morning came round the road was open again."
Twenty-seven people have died on Northland roads this year. It is unclear whether the Ohaeawai incident will add another death to the toll.
Dalzell said anyone who witnessed the incident can contact police on the 105 number.