One person has been flown to Waikato Hospital in a critical condition following a collision between a truck and a car near Cambridge.
The truck reportedly rolled after a collision with a car, and the driver was trapped in his cab for a short time.
Police attended the crash at 1.45pm on Cambridge Rd between Parallel Rd and Lamb St.
The driver was rescued and transported to hospital. No one else was injured in the accident, a police spokesperson said.
The road is currently closed and will remain closed for at least another three hours as the Police Serious Crash Unit and Commercial Vehicle Safety Team investigate.
Diversions are in place and motorists are asked to delay their journey if possible.
Earlier today fire and emergency shift manager Murray Bannister said it appeared the truck and trailer unit was carrying a load of potting mix which had also spilled onto Cambridge Rd, Leamington.
Emergency services were called to the scene, between Parallel Rd and Lamb St, at 1.35pm, he said.
"We are on the scene at the moment, we have two appliances there and three are responding, including our hazmat unit."
He said it was initially believed to be a chemical spill but it appears to be a load of potting mix.
The crash was initially called in as a truck rolled but after getting closer to inspect the scene, Burgess said it appeared a truck and a car have collided.
He said initially it was unclear what the truck was carrying.