SINGAPORE - A convicted rapist, who was on bail pending his appeal, has absconded to Thailand, the High Court heard on Monday (July 23).

A warrant of arrest has been issued for Ong Soon Heng, 41, who was sentenced to 13½ years' jail and 12 strokes of the cane last November for raping a drunk undergraduate in 2014 after driving her back to his home from nightspot Zouk.

The woman was 22 at the time and working as an intern at his friend's company.

After he was sentenced, Ong, a trainee bunker surveyor, was granted bail of $80,000 pending his appeal against the conviction and sentence.

The appeal has been scheduled to be heard in November.

However, in June, his landlord and brother, who was his bailor, could not contact him, the court heard on Monday.

His brother made a police report on June 21.

A separate "show cause" hearing will be held for Ong's brother to give reasons why the bail sum should not be forfeited.

Deputy Public Prosecutor Eunice Lau told the court that Ong's passport is still with the police and there are no official records of him leaving the country.

However, there were records of withdrawals made in Thailand from his bank account.

Ong's lawyer, Mr Sunil Sudheesan, told the court that he last saw Ong in April. Subsequently, they corresponded by e-mail.

Mr Sudheesan's application to discharge himself as Ong's lawyer was granted by the court.

In the early hours of July 24, 2014, Ong and the woman were at Zouk with friends.

Surveillance footage showed that he hauled her limp body over his shoulder at Zouk and placed her in the back seat of his car.

At about 4am, he took her to his house in Hume Heights, where he raped her while she was unconscious.

Her boyfriend found her in a stupor when he tracked her to Ong's home, using a smartphone app after she went silent on her phone.

Ong's defence was that the woman was not unconscious and had consensual sex with him.