SINGAPORE - A deliveryman who threatened a prostitute with a penknife was jailed 18 months for that and other offences on Friday.

A district court heard that Abdul Jalil Mohamad Yusof, 33, was driving a Mitsubishi lorry at about 2am on Oct 2 last year when he approached Chinese national Ms Yang Tianxin, 41, along Lorong 25 Geylang.

Using hand gestures and after some bargaining, he agreed to engage her services for $80. After she boarded his vehicle, he drove to an open car park along Genting Lane where he paid her and they began to smooch.

He then asked her for sex and Ms Yang asked if he had a condom. When he did not, she refused to continue her service, said Deputy Public Prosecutor Ryan David Lim.

During an argument, he grabbed a penknife from the dashboard and pointed it at her then drove out of the carpark. Ms Yang tried to release the door latch to leave but it was locked. She asked him to stop but he continued to drive.

She then tried to pull the steering wheel and gear stick to make him stop but he ignored her. Ms Yang then grabbed whatever she could find from the dashboard and threw them out of the lorry to make him stop - but he still refused.

She eventually managed to pull the steering wheel and caused the lorry to slow down before she jumped out while it was still moving, injuring her head, face, arms and legs.

That afternoon he was arrested at a Housing Board block in Ubi on suspicion of having taken drugs. Urine samples later confirmed he had taken methamphetamine or Ice.

He had also been driving while disqualified and was banned from the road.

He admitted four of eight charges. He had previous convictions for robbery, drug-related offences, criminal intimidation, snatch theft and repeatedly driving while banned.