SINGAPORE - A property agent has become the third man to be jailed for sex with a 15-year-old girl, joining a gynaecologist and a sales executive who were convicted earlier for similar offences with the same girl.

Lee Pok Seng, 44, was given 10 months' jail on Thursday for having sex with the girl at his home in Petir Road in mid-2012. He was then 42 and married.

Two other charges were taken into consideration during sentencing.

Deputy Public Prosecutor Sharmila Sripathy-Shanaz said Lee was looking for a "no-strings attached'' relationship when he posted an advertisement on a local website seeking sex.

Sometime in mid-2012, the minor responded and expressed an interest to meet him. He told her that he was 38 years old while she said she was still studying.

Subsequently, in a text message, she told him that she was 15 years old and in Secondary 3.

A few days after they first communicated with one another, he picked her up in the afternoon from a coffeeshop outside her school and drove the girl, still clad in her school uniform, to his flat.

When they got there, he told the girl that they should not have sex as she was only 15 but she disagreed. Ms Sharmila said Lee subsequently relented.

The incident came to light in May last year when the minor's father confiscated her mobile phone and saw messages of a sexual nature between Lee and the minor.

Earlier in February this year, gynaecologist Ong Theng Kiat, 63, was jailed for 10 months on two counts of having sex with the same girl. Ong, who suffered from major depressive disorder, had 11 other charges taken into consideration.

Last October, sales executive S. Ravi Chander, 49, was sentenced to 15 months for having sex with the girl on two separate occasions. Another two counts were taken into consideration.

The maximum penalty for sex with a girl under 16 years old is 10 years' jail and a fine.