A man may have been thrown from a car in an accident near Taihape in the early hours of yesterday morning.
Taihape fire chief Alan Troon said one man was about 25 metres from the car when they arrived at the scene about 1.30am.
Mr Troon was unsure whether the man had been thrown from the car or he had got out himself and moved away.
A police spokesman said the car rolled off State Highway 1 between Spooners Hill Rd and Paengaroa Rd and ended up in a paddock.
Mr Troon said the car was "still on its wheels" when they arrived.
A woman was still in the car and had to be extricated by firefighters.
Mr Troon said both people were conscious when emergency services arrived, but he could not say what condition they were in. It was unclear how the crash happened.
"Police were doing a bit of a scene investigation when we left this morning," he said.
The woman was flown by helicopter to Palmerston North Hospital, while the man was taken by road ambulance to Whanganui Hospital, said St John spokesman Mark Tregoweth.
St John territory manager John Stretton said the pair had "serious" injuries.
Yesterday afternoon the man was in a stable condition, a Whanganui Hospital duty nurse manager said.