“This incident requires a full-scale joint investigation involving both the KwaZulu-Natal community safety and education departments,” Democratic Alliance MPL Rishigen Viranna said in a statement.
“It is time that a very clear message was sent out that this kind of behaviour will not be tolerated.”
On Wednesday, the community safety department said it was investigating a video of the alleged gang-rape.
The video was circulated on social media, department spokesman Sipho Khumalo said at the time.
“We have not yet identified anyone and have to be careful to make sure the name of the school is not known, as this might lead to the victim being identified.”
He said the incident happened a week ago. He did not have further details on where in Pietermaritzburg it happened.
Police spokesman Colonel Jay Naicker said the case was being investigated by the SAPS child protection and sexual offences unit in Pietermaritzburg.
On Thursday, Viranna said the education department needed to conduct its own probe into how drugs and alcohol were allegedly available at the matric dance.
“It is saddening that this scourge continues despite the best efforts of many to change the way in which so many women are treated.
“It is essential that this young woman and her family receive the counselling they need.”