BHP has sacked the driver of a train which was deliberately derailed in Western Australia's remote Pilbara last year, carrying 30,000 tonnes of iron ore.

Key points: BHP claims the emergency brake was not engaged, meaning the train took off without the driver

BHP claims the emergency brake was not engaged, meaning the train took off without the driver The train had to be derailed remotely from Perth after travelling driverless for 90km

The train had to be derailed remotely from Perth after travelling driverless for 90km The driver was sacked just before Christmas, but is claiming he was unfairly dismissed

The fully-laden train, pulling 268 carriages, was derailed early on November 5, about 120 kilometres south of Port Hedland.

While the driver was out of the cabin, the train took off and travelled more than 90km before being derailed from BHP's Integrated Remote Operations Centre in Perth, about 1,500km away.

Two of the train's four locomotives were damaged in the derailment, along with 244 of the 268 carriages.

The driver was notified of his dismissal in the week before Christmas.

It is understood the man has lodged an unfair dismissal claim.

BHP iron ore president Edgar Basto said in November initial findings had shown the train had stopped automatically after a braking system control cable became disconnected.

The iron ore train was deliberately derailed by BHP . ( ABC News )

The driver was then asked to carry out an inspection, and the train started to move.

"Our initial findings show that the emergency brake for the entire train was not engaged as required by the relevant operating procedures," Mr Basto said at the time.

"The electric braking system that initially stopped the train automatically released after an hour while the driver was still outside.

"Due to integration failure of the backup braking system, it was not able to deploy successfully."

The wreckage of the train took several days to clean up. ( ABC News )

Mobile phone footage obtained by the ABC showed the twisted and mangled wreckage of the train lying strewn alongside the track.

In a statement released by BHP on Thursday, the company said that as a result of the preliminary investigations it had put additional interim safety controls in place.

It declined to comment on the unfair dismissal claim, saying it would not provide further information out of respect for the former employee's privacy.

Investigations by the ATSB and the Office of the National Rail Safety Regulator are continuing.