Four people were injured in a head-on collision at Ngunguru, prompting police to issue a warning about slippery roads after periods of hot weather.
Police spokeswoman Sarah Kennett said it appeared a car heading to Whangarei on Ngunguru Rd slipped on a patch of diesel as it rounded a sharp corner, and into the path of a car containing a toddler and a couple in their 60s.
The collision, which happened at 9.15am yesterday, about 20km from Whangarei near Kaiatea Rd, saw all four occupants of the cars taken to hospital.
A 39-year-old man was taken to Whangarei Hospital in a serous condition with chest pains, Ms Kennett said.
A woman in her 60s sustained moderate injuries with a suspected broken hip, while the man had a bad cut on his head. The toddler, a boy, was shaken with minor injuries.