[UPDATED on 19 December at 11:45am: adding information on man being charged]
The man who was arrested on Monday after jumping an MRT fare gate and wielding a samurai sword has reportedly been charged in court and was remanded at the Institute of Mental Health (IMH).
According to The Straits Times, Peter Chua Teck Choon, 39, was charged on Tuesday with possessing a scheduled weapon and was sent to IMH for a psychiatric evaluation.
When he was earlier identified by local media, internet users found his Facebook profile, on which he described himself "an expert swordsman" and a tattoo artist.
Images of him on his Facebook profile bear strong resemblance to one of the instructors, or sensei, of an Iaido club called Eishin Ryu Iaido Singapore. A check by Yahoo Singapore on the Eishin Ryu Iaido blog does list a "Peter Chua Sensei" as one of the club's two instructors.
On Monday, Chua, who appeared to be dressed up as a samurai and wielding a sword scared passengers on an MRT train when he boarded it.
According to a statement from train operator SMRT, the man "jumped the fare gate" at Paya Lebar MRT station, and brought a samurai sword on board the west-bound train.
"The male passenger was apprehended at 12:45pm around Bugis MRT station, and the incident is now under police investigation," said a spokesperson.
Eyewitness Julian Lim, a bank executive, recorded a five-second video of the man exiting the train.
He told Yahoo Singapore he had just boarded the north-bound train from Raffles Place with his colleague, when the unidentified man entered the train at City Hall MRT station, tailed by three transit security officers.
"It seemed like the officers were either following him or didn't want him on the train, or tried to talk to him about his sword," said the 35-year-old, who added that the man was talking to the officers, but he could not make out what language he was speaking or what he was saying.
"He (the man) didn't seem very happy with them, and they didn't seem very happy that he was carrying something like a sword," he said. "So at some point, he got agitated enough and drew his sword and started pointing it at one of the officers, and at that point everybody on the train, officers included, started to back away."
Lim described the man as being middle-aged and "slightly on the heavier side", with dyed and permed hair, and wearing a white T-shirt over what appears to be a hakama, a traditional Japanese garment.
He also described the sword as being black and matte, adding that none of the approximately 30 passengers on the train said anything during the brief episode.
"If he was (a cosplayer), he was very into character," he said. "I've never seen such an angry cosplayer before!"
According to Twitter user @swirlsof, who posted a picture to the microblogging platform, the man was heard "screaming something" while policemen on the train moved to protect panicked commuters.
More tweets showed that the unidentified man was apprehended by police outside Dhoby Ghaut station, where he was believed to have alighted.
@swirlsof's other tweets also claimed the man was "big size(d)" and was "threatening the police".
Yahoo Singapore has contacted the police for more information on the case.