A Blenheim man was airlifted to hospital on Saturday after he lost control of his motorbike north of Kaikoura.
The 28-year-old was travelling home from Seafest earlier in the day.
St John Kaikoura team manager Don Wright said the man lost control on a left-hand bend heading towards the Mangamaunu surf break.
Mr Wright believed the motorbike slid on its side into an oncoming car.
The man suffered multiple injuries, said Mr Wright.
He was treated at the scene by two intensive care paramedics, one prime doctor and one off-duty doctor.
No-one else was hurt in the collision, which happened just after 4.30pm.
The man was stabilised before being taken to the Kaikoura Medical Centre, from where he was airlifted to Christchurch.
Sergeant Julian Lewis, of Kaikoura police, said the cause of the accident was unknown and investigations were ongoing.
- The Marlborough Express