SINGAPORE - The SMRT staff member who had his foot amputated following an accident near Joo Koon station on Dec 12 was checking for oil leaks on the tracks when a maintenance train rolled over his foot.

In a statement to the media on Friday (Dec 21), the rail operator said the man was part of a six-member team that was preparing for a maintenance train to return to the depot after it had completed track tamping work, which involves machinery to push displaced gravel back under train tracks.

"The team was conducting a brake test on the maintenance train that comprises one locomotive on each side of a track tamping machine," said SMRT, noting that the test typically involves "limited movement" of the maintenance train.

The man - understood to be a 59-year-old SMRT veteran - was on the track to inspect for oil leaks from the maintenance train when it rolled over his right foot.

"The brake test was stopped immediately when one of the team members spotted the injured staff lying on the track," said the rail operator, adding that the rest of the team then went forward to provide first aid.

The brake test is a procedure to ensure that the locomotives and the track tamping machine are properly coupled and that the brakes are functioning before the move back to the depot.

The Singapore Civil Defence Force was activated following the accident and the injured man was taken to hospital, where the lower part of his right leg was amputated, said SMRT.

It added that he condition is now stable.

"SMRT takes a serious view of this workplace accident. We are assisting the Ministry of Manpower's Occupational Safety and Health Division in their investigation," said the rail operator.

Following the accident, a "safety timeout" - referring to a temporary halt to maintenance work - was put into place and a board of inquiry was convened.

National Transport Workers' Union executive secretary Melvin Yong, who visited the man, said he was in "good spirits" but concerned about his job.

"I advised him that what's most important now is to focus on his recovery. The union will discuss and work with the management on his future work assignment," said the Tanjong Pagar GRC MP in a Facebook post.

Last week's accident came two years after two SMRT trainees were killed by an oncoming train near Pasir Ris station in March 2016. Both men were part of a 15-member team on the tracks investigating a possible equipment fault.

Investigations later found that safety protocols which would have prevented their deaths were not in place, and SMRT was fined a record $400,000 for the incident.