Steve Welch of Armidale was only five minutes from dropping off his load of hay and was unaware that it had caught fire until a passing motorist flagged him down.

The incident occurred on the Devils Pinch just south of the Black Mountain roadhouse.

The fire spread quickly and within minutes had engulfed the cab of the table top truck.

Six heavy tankers and 25 voluntary fire fighters from nearby brigades responded to the 000 call.

They pulled the hay off the truck in a bid to stem the blaze but little could be done to save the load or the vehicle. Tractors were used to assist in breaking up the load.

The fire was so intense it melted the windscreen of the truck. Traffic was banked up for as far as 3km before one lane of the highway was reopened at 2 o’clock. It took fire fighters 8 hours to fully extinguish the fire.

Authorities are still investigating the fire, the cause of which remains a mystery, although spontaneous combustion is suspected.