A person has died in fiery crash after a truck rolled and caught fire on State Highway 1 south of Auckland's Bombay Hills.

The highway is closed in both directions at Bombay following the fatal accident, and police say the road is likely to stay shut until early this evening.

Police said the single-vehicle crash was reported at 11.40am, after the truck had reportedly rolled and subsequently caught fire near the Beaver Rd off-ramp.

The truck was travelling southbound at the time.

One person has died at the scene, said police.

"There was just a huge explosion and then a plume of smoke and fire," a nearby resident said. "And then explosion sounds twice again. It was so loud and there was smoke everywhere."

One person died in the crash. Photo / Auckland Rescue Helicopter Trust

State Highway 1 is currently closed in both directions between Mill Rd and Nikau Rd.

"The Serious Crash Unit is conducting an examination of the scene and there is a considerable amount of work required to clear the scene by emergency services and other contractors," said police in a statement at 2pm.

"It is anticipated the section of State Highway 1 between Mill Road and Nikau Road will be closed until this early this evening."

Southbound traffic is being diverted at the Bombay Hills, while northbound traffic is being diverted at Pōkeno.

Police reminded motorists undertaking any permitted travel today to allow plenty of time to reach their destinations safely.

More to come