"We were just called in case it was something more serious," he said.
Update 2pm: The truck involved in a collision with a ute has leaked a small amount of liquid onto the road.
Emergency services were investigating the potential for danger.
A police spokeswoman said the truck, which had rolled onto its side, was cleared from the road but police were directing traffic around the scene.
A Waikato police Facebook post said the occupant of the car had received a head injury.
Earlier: A truck is on its side and has collided with a ute on State Highway 29, Lower Kaimai.
Police and emergency services were called to SH29 near Hanga Rd and Rapurapu Rd around 1.20pm.
A police spokeswoman said it appeared one person was trapped but she was unsure of injuries.
The truck was blocking one lane and motorists travelling through the area could expect delays.