The misconduct apparently took place when the school's rugby teams were returning from Polokwane, where they had played in several matches.
A group of the older boys apparently abused and sexually intimidated a group of younger boys, and threatened them if they told anyone about the incidents.
The school said in a statement released on Wednesday that the junior players had been called in, to determine the nature and extent of the incidents.
In the presence of their parents
During the interim investigation certain players in the senior team who apparently had been involved to a greater or lesser extent, were identified.
The pupils appeared before a disciplinary team where they could put their side in the presence of their parents and Fanie Swanepoel, a lawyer whose services were retained by the school's management body.
Taking into account the extent to which they had been involved and their positions in the school, the following steps were announced against the boys involved:
Asked to comment, Professor Kobus Maree, a Pretoria educationist and clinical psychologist, said the punishment seemed to be appropriate and that the school had done well to take action immediately.