With "ItsmeDeedeeYourfrenlyfren" as his Facebook moniker, a Land Transport Authority security auditor preyed on young boys.

Soffiyan Hamzah, 38, performed oral sex on 10 boys, all minors below 18 years old, in public toilets and gave them up to $100 each for every encounter. He also had non-commercial sexual encounters with five other underage boys.

Yesterday, he pleaded guilty to eight counts of sexual penetration involving minors below 16. Seven other charges for similar offences and 68 counts of commercial sex with boys below 18 will be taken into consideration at sentencing.

Also to be considered are four counts of sexual grooming and three charges under the Films Act which include being in possession of 453 obscene films.

He committed the offences from mid-2015 to March this year.

Soffiyan was not the first man to have used the Internet to prey on young boys here.

In March 2015, engineer Yap Weng Wah, 31, was given 30 years' jail and the maximum 24 strokes of the cane for sexually abusing 31 boys from November 2009 to June 2012. It was Singapore's worst case of sexual abuse of young boys.

The Malaysian befriended his victims, who were between the ages of 11 and 15, online before cajoling them into performing oral sex or letting him sodomise them.

In the latest case, Deputy Public Prosecutor Gail Wong said Soffiyan was known to his victims as "Dee" or "Dee Dee". None of them knew his real name. In his Facebook profile, he said he was gay and would perform oral sex on anyone. He also stated that he would pay.

The court heard that Soffiyan got to know some of the boys through his victims. After the boys agreed to meet him for oral sex, which Soffiyan referred to as "work", he would usually arrange to meet them near MRT stations.

The court heard that most of the sexual encounters took place in a toilet at JCube shopping centre in Jurong. He would meet his victims after cleaning hours or late at night close to or after mall closing hours, when there was less human traffic.

DPP Wong said: "On some occasions, the accused would meet more than one boy in the same session, who would wait in different cubicles for him."

In January, one of his victims, 16, introduced his younger brother, then 15, to Soffiyan. The younger boy then met Soffiyan twice.

The case came to light after the boy told his teacher about the encounters. The teacher alerted the police on March 10 and Soffiyan was arrested three days later.

Soffiyan's case has been adjourned to Jan 3 next year.