SINGAPORE - A man ordered a taxi driver to hand over all of his money after threatening the elderly man with a weapon - only to make off with just $36 from the cabby.

Li Han Cai was initially accused of robbery and could have been sentenced to up to 14 years' jail with mandatory caning of at least 12 strokes if convicted of the offence.

On Monday (Jan 6), he pleaded guilty to one count of the less serious charge of extortion.

The 37-year-old Singaporean was sentenced to two years and three months' jail with one stroke of the cane.

For extortion, he could have been jailed for up to seven years and receive mandatory caning.

On March 29 last year, taxi driver Tan Guan Wah, 72, started his shift at around 1am and picked Li up in Geylang Lorong 27 about 30 minutes later.

Mr Tan drove to Li's destination in Punggol Central and the younger man asked him to drive into a carpark.

The cabby told Li that the fare was $20.06 but he would accept $20.

Deputy Public Prosecutor Seah Ee Wei said: "The accused then grabbed the complainant from behind. (He used) his left hand to grab the side of the complainant's neck and placed a sharp object on the right side of his neck."

Li asked Mr Tan for all of his money and took $36 from him. Court documents did not disclose what exactly was the object used by Li to threaten the cabby.

Li then took the key for the taxi and tossed it into the bushes after he got out of the cab, the court heard.

At around 2.20am, Mr Tan called the police. Officers retrieved the key which had Li's DNA on it.

Court documents did not state, however, if his DNA was used to track him down.

DPP Seah told District Judge Toh Han Li that Li has since made a restitution of $36 to Mr Tan, who was not injured in the incident.

The $20 fare remains unpaid.

Defence lawyer Wee Hong Shern told the court on Monday that his client is "thoroughly remorseful for his wrongdoing".

He added: "His foolish actions in gaining such a little sum of money has cost him dearly."

Li is now out on bail of $20,000 and will surrender himself at the State Courts on Jan 28 to begin his jail term.