Johannesburg - Vusi Ernest Mabaso, one of the men accused of killing seven family members from Vlakfontein and raping some, was found hanging a police cell.
Mabaso committed suicide on January 18 at the Cape Town Central Police Station.
Gauteng Community Safety spokesperson Ofentse Morwane said the case against Mabaso was "quite complex" and he had been taken to Cape Town as part of the broader investigations into it.
However, police found him dead on January 18.
"He hung himself," Morwane said.
Mabaso and his co-accused, Fifita Khupe, were supposed to appear at the Protea Magistrate's Court on Thursday morning on multiple charges of murder, rape and robbery. They were to apply for bail.
The court, however, was informed that Mabaso was dead.
Khupe and Mabaso were arrested last year after the seven family members, including children, were found dead and buried under heaps of sand inside the house.
At the time of the murders, Khupe was in a romantic relationship with one of the victims.