UPDATE – 11.30am: A truck driver has sustained moderate injuries after his trailer unit rolled on State Highway 33 this morning.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says the truck and trailer had been travelling towards the new Paengaroa roundabout when the trailer rolled.

A truck has rolled on SH33, near Paengaroa. Photos: Ryan Carlyle.

'For some reason the trailer has overturned and the load of timber it was carrying has fallen over the roadway,” says Ian.

'The truck was the only vehicle involved and the driver is in the process of being transported to Tauranga Hospital for observation.”

Police and emergency services are currently at the scene and a diversion through the Fruit Lands forecourt on SH33 is now in place.

Ian says traffic is currently following reasonably freely through the scene of the crash but expects the diversion to be in place for a period time while the timber and trailer unit are recovered.

A lamp post near the roundabout is believed to have suffered damage as a result of the crash and PowerCo have been called to the scene to assess the damage.

EARLIER:

Power lines are down and live wires have been left exposed after a truck rolled on State Highway 33, near Paengaroa.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says it appears one truck and trailer unit is involved in the crash.

"The westbound lane is blocked. It appears two truck may be involved," says Ian.

"Information from the NZ Fire Service is that one truck has rolled and one is upright."

Ian says police are at the scene.

One of the trucks involved appears to be a B-train carrying a load of timber.

A witness says the truck was carrying around six tonne of 4X2 timber.

Motorists are being warned to expect delays until the scene is cleared.