SINGAPORE - A student with an underwear fetish walked into a condominium in his neighbourhood in the wee hours of the morning, and managed to enter a ground-floor unit through its open balcony door. He went to the maid's room and started smelling one of her bras, but bumped into her bed frame and woke her up.

Zach Sim Chu Hong, 18, fled the home but was caught by police soon after. He pleaded guilty on Friday to house trespass at Pine Grove condominium in Clementi on Apr 11.

The court heard that Sim had decided to look for underwear after watching pornography at his nearby HDB flat, around 2am that day. He entered the condo by its main gate and targeted the condo unit, after noticing its balcony door had been left open. During investigations, Sim said he initially took clean underwear from Pine Grove units to smell, but later preferred them pre-worn. He also preferred garments that belonged to midde-aged women and would would target homes based on the laundry hanging outside.

Sim's lawyer Josephus Tan said his client has been diagnosed with a "fetishistic disorder" and low intelligence.

Sim, who admitted to a further charge of trespass at another Pine Grove unit in February - this time entering through a toilet window - will be sentenced on Oct 3 after the court called for a pre-sentencing report.