A dead body was found lying in an MRT tunnel between Redhill and Tiong Bahru stations on Sunday evening, according to local media reports.
It's unclear how he got there but the body is believed be of a Chinese man in his 20s. He was found lying beside the train tracks.
The gruesome discovery led to train services running in both directions on the East-West line from Queenstown to Outram Park to be disrupted for about two hours.
In a media statement, SMRT said trains stopped running at 823pm to allow the police to investigate the incident.
Eastbound services was thereafter suspended intermittently between 914pm and 1017pm to facilitate police and SCDF investigations.
In its statement, SMRT said services were disrupted due to a "one-under" incident, a term which is commonly used by rail networks to describe a person under a train.
The situation could arise from a deliberate act or by accident.
Investigations are ongoing.
The Pollutant Standards Index (PSI) hit a new record high of 371 at 1pm on Thursday, again climbing into the "hazardous" range of above 300, according to data from the National Environment Agency (NEA).