SINGAPORE - A man who had underage sex with a minor - the fifth to do so - was jailed for 12 months on Friday.

Ngo Choon Seng, 30, had admitted to having sex with the 15-year-old girl in his car which was parked at the top deck of a multi-storey carpark on Oct 13, 2012.

A second charge of using a vibrator to penetrate her was taken into consideration during his sentencing.

The court heard that the victim, who was in Secondary 4, created an account on Blendr, a social networking application, sometime in mid-2012 as she wished to make more friends. She indicated she was 18, as this was the minimum age allowed for registration.

She began communicating with Ngo, then an executive sales operator, on Blendr sometime in September that year. She told him she was 15 and still studying.

Soon after befriending one another, Ngo sent the minor a nude photograph of himself via WhatsApp. He then began talking to her about sex.

She reciprocated and they subsequently agreed to meet for sex on condition that he wore a condom.

On the afternoon of Oct 13, 2012, as arranged by Ngo two days before, he picked up the minor from her home in his car and drove her to a multi-storey carpark where he committed the offence.

The duo ceased communication after this incident.

Four others linked to the victim in the present case had received 10 to 15 months' jail for similar charges.

The incidents came to light after a church friend informed the minor's father that sexually explicit photographs of the minor were circulating on the Internet.

A police report was lodged in December 2012 after the minor's parents brought her to KK Women's and Children's Hospital for a precautionary medical check-up.

Ngo was diagnosed with a a major depressive episode which was of "moderate severity". A doctor had said at a Newton hearing that Ngo made a conscious choice to meet the girl.

Ngo, who works as a seafood deliveryman, could have been jailed for up to 10 years and/or fined for having sex with a person under 16 years.