A 45-year-old man suffered serious head injuries in a motorcycle crash at Taupo Motorsport Park.
The Waikato Westpac Rescue Helicopter with an intensive care team was called to Taupo Hospital to retrieve the Taranaki man about 3pm yesterday.
He was initially treated at Taupo Hospital before being flown to Waikato Hospital for further treatment.
Track manager Ian Bowater said neither he nor his staff were there on the day, as the track had been hired out privately.
"The track is signed over and it's just a normal private hire," he said. "It was on a Sunday and we don't work on the Sunday unless we're organising or running the day ourselves."
The track had been hired out to a driver training program, he said.
In May last year, a Ferrari driver died after hitting a wall at the Taupo Motorsport Park.
He was estimated to have been driving at 190km/h at the time.
Mr Bowater said despite the two incidents, there were no safety concerns at the track.
"The track is 100 per cent up to its license standards," he said.