A Nanyang Technological University graduate was sentenced to nine weeks' jail for engaging in commercial sex with an underage girl.

Ernest Lee Min Chong, 25, is released on $10,000 bail, pending his appeal against sentence.

He had admitted to paying $60 for the sexual services of the 17-year-old Chinese national at Min Wah Hotel in Lorong 22 Geylang on a day between May 20 and 24 last year.

More than 20 men have been convicted of engaging in paid sex with the minor, who was forced into prostitution by her pimp, Tang Huisheng, 37, also from China.

The court heard that before the minor's father died in October 2011, he had undergone treatment for cancer and borrowed RMB100,000 (about $20,000) from relatives and illegal moneylenders for his medical treatment.

The burden to repay the debts fell on the minor and her mother. The Shandong native subsequently travelled to Macau to earn more money. She ended up in Zhuhai where she met Tang who drugged her once with methamphetamine (Ice) and had sex with her while she was in a stupor. He repeatedly asked her for sex and would threaten or beat her up if she refused.

On May 16 last year, he flew to Singapore with the minor and brought her to Geylang where she solicited for customers. He acted as a lookout and helped her to get customers. Tang, who has been dealt with, would collect all her prostitution earnings at the end of each day.

Investigation showed that on a day between May 20 and 24 at about midnight, Lee went to Geylang and saw the minor soliciting at the junction of Lorong 22 and Geylang Road. She approached him and offered him sexual services for $60.

They proceeded to Min Wah Hotel where they had sex. He had asked for her age and she told him that she was 20 years old. But he did not take any steps to verify her age.

Counsel Ranjit Singh had asked the court to call for a probation report but Deputy Public Prosecutor Sharmila Sripathy-Shanaz strenuously objected to this.

Ms Sharmila said past cases showed that probation has been ordered in similar cases where the offender was either below 21 at the material time, or had a psychiatric condition.

Lee, she said, was 24 at the time and was not suffering from any mental illness.

The maximum penalty for paid sex with a person under 18 years old is seven years' jail and a fine.