A taxi driver found with critical head injuries in the boot of his car had been kidnapped, according to Taranaki police.
The Waitara man, 49, was found on Friday morning by periodic detention workers in a carport at Urenui Primary School, 30km northeast of New Plymouth.
The taxi's roof light was on and after hearing a noise, the workers tapped on the boot, calling emergency services when the man inside responded.
Detective Senior Sergeant Grant Coward says the man suffered severe head injuries and was incoherent, distraught and very weak when found.
Mr Coward says police want reports about the movements of a white Toyota Camry, registration T-A-X-1-1, from before midnight, when the driver last called his dispatcher at Egmont City Cabs, until 8.45am on Friday when he was found.
Police particularly want to hear from anyone who rode in the taxi.
Forensic police are examining the scene where the driver was found.