Police suspected alcohol was too, but this still had to be confirmed, Cooper told Fairfax.
Four people have now died on the road this Christmas holiday road toll period, which began at 4pm on Friday and ends at 6am on January 3.
"It's the decisions we make that are costing lives. We're making poor decisions behind the wheel. You've got to think when you drive," Cooper said.
Hanmer Springs Volunteer Fire Brigade chief fire officer John Donaldson was first on the scene with his brigade of two trucks and around 10 firefighters.
The car was heading towards Hanmer Springs when it crashed "right outside the entrance" of the Hanmer Springs Forest Park, about 2 kilometres from the township.
Donaldson told Fairfax firefighters found the car wrapped around a tree and "smouldering".
"It was on fire in some places underneath from the grass and electrical components".
"If you can imagine the gear lever in the centre of the car, that's basically where the tree was sitting. . .The car was basically just about folded in half in some areas because of the impact of wrapping around the tree."
Firefighters effectively had to "dismantle" the car, including removing the roof, to reach the injured passenger. They gave the man first aid until St John paramedics arrived and took over, Donaldson said.
The Nelson Marlborough Rescue Helicopter flew the man to hospital.
Donaldson said there was rain about 5pm on Saturday and the road was slightly wet as a result.
The police serious crash unit is investigating the cause of the crash.
