Four people have been injured as a result of a major crash involving a van and truck-and-trailer unit on Matakana Rd, near Warkworth.
An Auckland Westpac Rescue Helicopter spokesman said that the rescue helicopter crew were called to assist in the motor vehicle accident around 12.30pm.
"It appears the vehicle collided with the truck trailer. The truck driver was unharmed.
"There were four patients and we attended to a boy who was in a critical condition," he said.
The boy suffered severe leg injuries and was given whole blood by the crew before he was flown to Starship hospital in a critical condition.