Chauke said when he arrived at the scene‚ he asked the police where his nephew was - but they didn't immediately give him answers.
"Then I saw him‚ lying there‚ helpless‚" said Chauke‚ breaking down.
Asked what kind of person Kulani was‚ his uncle simply said : "He had a bright future ahead of him".
"To think it would end like this... I expected a lot from him‚" Chauke continued.
While paramedics had earlier said that the stab victim was a 16-year-old boy‚ his family clarified that he was actually 19 years old.
Kulani was said to be the grandchild of renowned XiTsonga musician Thomas Chauke.
One of the last people to have seen him alive was his school principal Vangelia Nicolaou‚ who rushed to the scene after hearing of the stabbing.
"I am distraught because it it terrible for a mother to lose a child‚" Nicolaou told reporters at the scene.
Recalling Kulani's last moments alive‚ she said the wounded youth did not say anything.
"I could feel his pulse. I could see he was still alive but I could see he was going‚" she said.
Kulani was later certified dead by the paramedics‚ who said all efforts to revive him had failed.
'Why did they take my one and only child‚' cries mom of Mondeor stab victim
The piercing cries of Kulani Mathebula's mother pierced the silence of the quiet Mondeor surburb in the south of Johannesburg on Wednesday afternoon.
"My one and only child. Why did they have to take him away from me? " Dumi Chauke cried as she was led into a vehicle parked just meters away from her son's body had just laid.
"Kulani! Kulani‚" the 36-year-old woman wailed as she walked away from the mortuary van.
She and a female relative were distraught as they came to see Kulani's body being removed from the spot where he took his last breath.
Kulani had been stabbed‚ reportedly three times in the chest‚ just minutes after he left home to go to school.
His uncle‚ Themba Chauke‚ had told the media that he was shocked when he received a distraught phone call‚ telling him to rush to the scene as Kulani had been stabbed.
"I just received a call this morning from my younger brother. He was just crying uncontrollably saying‚ 'brother‚ they've stabbed Kulani. Come quickly.'"
Chauke said when he arrived at the scene‚ he asked the police where his nephew was - but they didn't immediately give him answers.
"Then I saw him‚ lying there‚ helpless‚" said Chauke‚ breaking down.
Asked what kind of person Kulani was‚ his uncle simply said : "He had a bright future ahead of him".
"To think it would end like this... I expected a lot from him‚" Chauke continued.
While paramedics had earlier said that the stab victim was a 16-year-old boy‚ his family clarified that he was actually 19 years old.
Kulani was said to be the grandchild of renowned XiTsonga musician Thomas Chauke.
One of the last people to have seen him alive was his school principal Vangelia Nicolaou‚ who rushed to the scene after hearing of the stabbing.
"I am distraught because it it terrible for a mother to lose a child‚" Nicolaou told reporters at the scene.
Recalling Kulani's last moments alive‚ she said the wounded youth did not say anything.
"I could feel his pulse. I could see he was still alive but I could see he was going‚" she said.
Kulani was later certified dead by the paramedics‚ who said all efforts to revive him had failed.
When reporters had earlier arrived at the scene‚ the sole of his now-pale foot was protruding from the silver foil which had covered his body.
His blue school bag was placed close to his body.
Forensic pathologists were combing through the scene. At one point‚ they opened the foil to take pictures of his lifeless body‚ leaving the community members and concerned parents from the school shaken.
It is still unclear what the motive of the attack was.
Gauteng education MEC Panyaza Lesufi‚ who visited the school after being alerted to the incident‚ expressed confidence in the police.
He said the police had since secured footage from different sources which showed three possible suspects behind the attack.
"The sad thing is that with the current footage we have‚ we have zeroed in on three other learners from other schools in the area‚" said Lesufi.
"But whether it's them‚ we are not sure‚" Lesufi said‚ adding that he was reluctant to speculate.
Meanwhile‚ police could not immediately confirm whether anything had been taken from Kulani during the attack.