In a statement, the Australian Transport Safety Bureau (ATSB) said: 'The driver alighted from the locomotive to inspect an issue with a wagon. While the driver was outside of the locomotive, the train commenced to runaway.
'With no one on board, the train travelled for 92 km before being deliberately derailed at a set of points operated by the control centre, about 119 km from Port Headland (near Turner siding).'
A BHP spokeswoman told The West Australian no one was injured and authorities are investigating.'