Two men who had paid sex with a 16-year-old student were each jailed for 12 weeks on Wednesday in another online vice ring case.

Former port inspector Alvin Chen Zi You formerly known as Tan Zi Yu, 32, admitted paying $230 for the sexual services of the minor at Oxley 88 Hotel in Geylang on Feb 18.

The other man, bell hop Muhammad Ibrahim, 24, pleaded guilty to paying $180 for her services at his flat in Tampines on Feb 24.

A district court heard that the alleged pimp, Malcolm Graham Head, 32, started a company called "Wet Dreams'' last September to procure females for prostitution after his release from prison. He was assisted by his girlfriend, Veronica Patricia Rio, 18.

He operated his online ring prostitution services by advertising the sexual services of his working girls on various websites.

In October last year, he befriended the minor via Facebook and tricked her into believing that she was going to be a social escort with "fast cash'' and "high pay''. The secondary school student was told that her role was to accompany clients for functions and dinner only.

Subsequently, she realised that she had to provide sexual services of all kinds to clients secured by the couple who were assisted by Ahmad Habiibul Hakim Assalafi, 19.

At times when the minor did not want to serve clients, she would be fed "Ice'', the common name for methamphetamine, to keep her awake or she would be beaten up.

The screenshot advertisement stated that the minor's age was 22.

Chen, who is married, and Muhammad could have been jailed for up to seven years and/or fined each.

The cases against the pimps and two others are at pre-trial conference stage.