Luckily the worker was able to put out the flames with a hand-held fire extinguisher.

He was refuelling the diesel pump during commissioning when the auto-fill nozzle clicked off, showing the tank was full.

However, with the fuel gauge saying it was only 87% full, he pushed the nozzle back on and held it in position to continue filling the diesel tank.

Diesel then started flowing out of the pump's breather, so the nozzle was disconnected, and the hose reeled back onto the truck.

Fuel then came into contact with the pump's exhaust lagging and ignited.

According to the NSW Resources Regulator, workers should never override safety devices when refuelling.

The regulator said this included repeatedly filling after the nozzle has clicked off, tying the nozzle handle back to avoid holding it or modifying nozzles to fill machines that are not compatible.

Breathers should also be positioned clear of ignition points and hot surfaces.