A 30-year-old jobless man pleaded guilty in the High Court on Monday to raping and robbing - at knifepoint - a young woman on her way home.

In the early hours of Nov 16, 2010, Tan Jun Hui, decided to rob the woman, then a 21-year-old civil servant, when he saw her at the lift lobby of her block of flats in the western part of Singapore.

After taking a 21-cm knife from his car, he dashed into the lift with her. When she was about to get out of the lift on the second floor, he pulled her back in and threatened her with the knife. When the lift opened again on the ninth floor, he robbed her of her two mobile phones and $200. Tan then tried to force her to perform oral sex on him before raping her at the staircase landing.

Tan later got an acquaintance to help him sell the phones. This ultimately led to his arrest as the police followed the trail of the phones. He will be sentenced on April 24.