Interim results of a post-mortem on the body of a woman found outside a hospital in rural Waikato show she died immediately at the scene of a crash in the Kaimai Ranges.
Jovaan Rahera Graham, of Tauranga, was found by security staff outside the private Pohlen Hospital in Matamata at 4am on Wednesday.
Police believe the 18-year-old's death is linked to a string of events including a car crash on State Highway 29 in the Kaimai Ranges, an assault and the theft of a car.
They say the driver of the vehicle that struck Ms Grahamn was abducted and assaulted.
Police say a number of people have come forward with relevant information but would still like to hear from two truck drivers who were travelling along the Kaimais when the victim of the abduction attempted to flag them down.
A man and a woman have been charged with aggravated robbery, kidnapping, injuring with intent to injure and stealing a car after appearing at the Manukau District Court on Wednesday.
Police are making arrangements to return Jovaan Graham to her family.
