Tshwane north education district's chief psychologist, Christo Pretorius, said this emerged when he and his colleagues had a session with pupils from David "MoDav" Hlongwane's Grade 10 class.

"They are scared because of what happened to David. They are worried that what happened to him might happen to them as well, but we assured them and they understood afterwards that it was safe to come to school and that there was no reason to be scared," he said.

Hlongwane, a pupil at Lethabong Secondary School in Soshanguve, north of Pretoria, hanged himself last Wednesday, rather than go to school and face the boys who had bullied him.

Four Grade 10 pupils allegedly attacked him twice last Tuesday.

Department of education officials were also at the school yesterday to offer their support, but would not discuss details of their meeting with the principal.

David's mother, Sheila Hlongwane, said she was called to the school two weeks ago after her son got into a fight with his cousin.

"This matter was resolved there and then. The second time I was called to the school, the notice did not reach me and we only found this inside David's pocket after he had hanged himself," she said.

David's sister, Bongi, said she had learnt on Monday that the boys who tormented her brother had accused him of taking a cellphone that belonged to a cousin of one of the boys .

The education department said it would appoint a private law firm to investigate the matter.

Spokesman Charles Phahlane said it took this route "because we want everybody to have confidence [in] the outcomes of the investigation".

He said trauma counsellors were at the school and had also offered their services to the family.