A second person is dead as a result of a weekend crash on Whangarei Heads Road.
A seven-year-old girl, who was critically injured in the crash, has died in hospital.
Her mother was killed when the car driven by her partner hit a tree, on a left-hand bend heading into Onerahi.
The man is recovering in hospital - a second daughter suffered moderate injuries.
Police say their investigation is in its early stages and no charges have been laid as yet.