A German woman on holiday in New Zealand to visit her daughter was killed in a crash in Matakana, north of Auckland, yesterday.
Police said the three occupants of the car that left Leigh Road and crashed in to a tree stump yesterday were all from Germany.
The driver was a 19-year-old woman who had been living in working in New Zealand since July last year.
She remained in a critical condition in Auckland Hospital, police said.
Her mother, who was 48, was killed the crash, and her father, 48, is in a stable condition in Auckland Hospital.
Police said the cause of the crash was being investigated and inquiries into the type of licence that the driver held will form part of the investigation.
Interpol were helping to advise family members in Germany and Police would release the victim's name once family had been notified.
Inspector Mark Fergus said: "We appreciate that there is often significant public interest in crashes involving foreign drivers however at the moment we need to let our investigation run it's course and what happened here will only be known once that has been completed.
"Yesterday afternoon's series of car crashes on Waitemata roads are the stark reminder of the need to take extra care behind the wheel during bad weather.
"More rain is forecast over the long weekend and Police are urging all drivers, particularly anyone heading north, to slow down."
Mr Fergus said the roads in the Rodney area have some of the highest volumes of traffic on long weekends.
"You've got hundreds of Aucklanders heading north to the beaches and through the Puhoi tunnel, and out west on State Highway 16 to Muriwai. We hope that if anything can come out of yesterday, it's that people will actually slow down.
"It sounds so obvious but we've all experienced the drivers who fly past us as it's bucketing down, leaving us shaking our heads."
The crash in Matakana was one of a number of crashes yesterday on wet roads around Auckland.
A school bus slid off the road in Manly, blocking both lanes of Whangaparaoa Rd and cutting power to houses about 4:20pm yesterday.
An elderly man was taken to hospital with head and leg injuries after his car veered off Atkinson Rd in Titirangi and rolled down a bank about 4.30pm, and a young woman suffered moderate injuries after the car she was driving hit a power pole in Te Atatu South about 5.51pm.