At least three pupils, all girls, are said to have been forced to perform oral sex on a housemaster as a form of punishment, Sin Chew Daily reported.
The victims, all aged 11, from Bintulu, Sarawak, were forced to strip and perform oral sex on the man during the last six months.
When the victims first refused, the suspect told them that they had to do it as a punishment for being undisciplined.
The incident came to light when one of the victims told her problem to another pupil. They later found out that more pupils were victims.
The police are now investigating the case after the children's parents lodged reports.