Keamohetswe Seboko died last Wednesday during a swimming lesson in the hostel pool at Laerskool Bekker in Magaliesburg.
However, the Gauteng Education Department was informed of Semoko's death days later.
Officials say counselling is being provided for affects pupils and school personnel at the premises.
Gauteng Education MEC Panyaza Lesufi told the media on Sunday afternoon that Seboko's family had many questions and feel that there are things that are unexplained.
Bongani Bingwa chats to advocate Tiny Seboko, the deceased's aunt to give more insight on the matter.
What happened to him is indescribable and there is still no explanation of how the child died.— Advocate Tiny Seboko, Keamohetswe Seboko's aunt
Seboko says she dropped her nephew and two other girls off at school the day before as he was a boarder at that school.
I remember enquiring about swimming lessons for the two girls as Kamo has been able to swim since he was four years old. He was a confident swimmer who could swim unsupervised.— Advocate Tiny Seboko, Keamohetswe Seboko's aunt
She says the family then phoned the next day to be told that their child had drowned and no one saw how the child drowned.
The mystery of it all is that Kamo had sustained an open wound at the back of his neck and the top of his head.— Advocate Tiny Seboko, Keamohetswe Seboko's aunt
Listen below to the full conversation: