The Nelson Marlborough Rescue Helicopter was returning from Wellington about 4.40pm when it was diverted back to Blenheim to a mountain bike accident on the Wither Hills walkway.
A 25-year-old mountain biker from Palmetston North had suffered head and shoulder injuries when he crashed off his bike.
A helicopter service spokesman said St John Ambulance and a Rural Fire crew had been able to get to the man scene by four-wheel-drive vehicle and provide inital care but the man's injuries and the terrain meant it was not practical to get him out by vehicle.
The rescue helicopter was able to land at the scene and lift the patient for the flight to Wairau Hospital, in Blenheim. His condition was not available this morning.
- The Marlborough Express