A contractor who threatened to throw his friend from the 11th-floor common corridor was jailed on Wednesday.

Besides threatening Madam Juliana, 25, the accused Koh Choon Lian, 40, also slapped her twice on the face. He had pleaded guilty to four charges.

A district court heard that he went to the housewife's flat in Yishun last Oct 22 and kicked at the door.

When Madam Juliana appeared at the door, he asked her for $2,000 but she refused. He became violent and threw a flower pot at the window, causing the glass to shatter and damaging the window panel.

He then continued to kick at the metal gate and demanded to be let in. He threatened to throw her off the parapet. Madam Juliana opened the gate to let him enter so that he would not create a scene,

Once inside, he kicked the electric fan and took her mobile phone and bunch of keys from the table. He dragged her to the lift, and at the ground floor, demanded $2,000 from her again but she refused. He slapped her and punched her on the shoulder.

Madam Juliana called her mother-in-law who called the police. When Staff Sergeant Ricky Lau Jixiang, 28, and his partner came, Koh behaved aggressively.

The officer tried to calm him down. Koh shouted that the victim had owed him money and ran to the back of the block.

Subsequently, the cops caught up with him. Koh then punched Staff Sgt Lau, whose spectacles fell off. Koh was eventually arrested after a short chase.

The court backdated Koh's total five-month sentence to his remand on Oct 24.