A 31-year-old Chinese national allegedly raped and sexually assaulted at least five teenage girls aged 14 to 19 years old between last September and June this year - nearly one offence each month.

Lin Rongxin, who is currently in remand for psychiatric assessment, appeared in court yesterday via video link. He is facing seven counts of rape and one of sexual assault by penetration.

Some time between September and December last year, Lin allegedly raped an 18-year-old girl in a cubicle of a men's toilet on the seventh storey of Block 1008 Toa Payoh North, an industrial building.

He allegedly returned to the same toilet later that year, where he raped a 14-year-old in October and violated a girl of the same age in November.

In March this year, and subsequently some time between May and June, two more girls were raped in the same toilet, the court documents state. The victims were 17 and 14 years old.

Last December, he also allegedly raped a 14-year-old girl in a unit at Bishan Loft.

In February this year, he victimised a 15-year-old girl at an undisclosed location in Toa Payoh.

Then, in May this year, a 19-year-old girl was raped in a room at Balestier Hotel in Balestier Road.

When The Straits Times visited the industrial building yesterday, an employee working on the seventh floor said she saw police leading a male suspect to the men's toilet on the same floor last month.

The building's management gives tenants keys to the toilets but they say the male toilets are largely left unlocked out of convenience.

• Additional reporting by Cara Wong