Police are unsure at this stage what caused the crash but investigations are continuing. The child's mother and another female passenger were injured in the crash and taken to Hawke's Bay Hospital for treatment.
All three were from Flaxmere.
Mr Foley said part of the investigation will include obtaining a blood sample from the driver and determining whether or not another car was involved. The highway was closed from Omahu Rd to Longlands Rd and traffic was diverted at those two roundabouts while crews cleared the crash site.