SINGAPORE - A recalcitrant molester released from prison in March was caught outraging a woman's modesty on an MRT train just four months later in a video that went viral.

Sim Teck Chye, 45, who has been in and out of prison every year since 2013 for molestation, was last sentenced to jail in January this year.

On Tuesday (Dec 5), the jobless man was jailed for six months after admitting that he had touched a woman's thigh while riding on a train along the East-West Line on July 2.

The incident was captured in a video and photos which went viral online.

Another woman, who remembered Sim from a separate incident, recognised him from one of the photos.

Shortly before the July 2 offence, Sim had boarded a train on the North-South Line on June 30 and stood close to the second woman, who is known only as Ms Lim, 27.

She felt uncomfortable and turned her body away.

The train suddenly slowed down and jerked as it was reaching Yishun MRT station. Sim lost his balance and his right forearm then touched Ms Lim's right upper arm.

However, she did not seek help as she assumed it was an accident.

Three days later, Ms Lim received a website link from a friend and saw a picture of Sim molesting a woman on a train when she clicked on it.

She recognised him as the person who had earlier touched her and alerted the police later that day.

Deputy Public Prosecutor Michael Quilindo told the court on Tuesday that netizen Winna Chin had captured the photographs and a video of Sim committing the offence.

Ms Chin uploaded them onto her Facebook page and posted an accompanying message warning others to be careful of Sim.

The images became viral after another netizen, known only as Andy, alerted citizen journalism site Stomp about them.

Police arrested Sim at Hougang Mall on July 5 and he admitted in a statement the next day that he had molested the woman in the video.

DPP Quilindo said Sim suffers from obsessive compulsive disorder but his mental condition was not linked to his offence. The court also heard that the woman in the video was not traced by the police.

Sim's lawyer, Ms Ariel Lim, who was assigned the case under the Criminal Legal Aid Scheme, pleaded for her client to be jailed for a maximum of four months.

She said that Sim wants to change and intends to seek treatment to address his disorder.

For molesting the woman, he could have been jailed for up to two years and fined or caned.