Johannesburg - A Soweto primary school, where at least 87 pupils were allegedly sexually assaulted by a security guard, has been rocked by another controversy - this time it involves the arrest of a police investigator assigned to the case, allegedly for similar crimes at the same school.

This was according to the Gauteng education department on Tuesday, which said the SAPS forensic investigator was alleged to have abused two pupils at the AB Xuma Primary School.

Department spokesperson Steve Mabona said the incident allegedly occurred on Monday, March 12 when the officer visited the school to prepare the young victims for court.

"It is alleged that the investigator sexually molested the two Grade 3 [pupils], aged seven and eight years old, respectively," he said.

"The children have now become victims of sexual assault twice by different people."

The matter was escalated to Family and Child Services, where the pupils and their parents were interviewed.

"The said [officer] has been withdrawn from the case with immediate effect and a sexual assault case was opened against him by the parents at the Orlando police station."

Education MEC Panyaza Lesufi described the allegations as shocking and disturbing.

"A person entrusted with protecting children has violated their trust and that of their parents. This man should meet the full might of the law."