King Xolilizwe Sigcau of the Xhosas died at Number One Military Hospital in Pretoria on Saturday night, South African Broadcasting Corporation radio news said on Sunday.
According to the report, the 79-year-old king died after suffering a long period of health problems.
The royal house is waiting for a post-mortem to determine his cause of death.
The king’s brother, Prince Xhanti Sigcau, said members of the royal house were still in consultation and funeral arrangements would be made in due course.
Meanwhile, President Thabo Mbeki has conveyed his heartfelt condolences on behalf of the government and South African people.
Presidential spokesperson Murphy Morobe said on Sunday that Mbeki had an opportunity to visit the king in hospital before his passing.
”King Sigcau will be sadly missed for his leadership and counsel to his people.”
The president wished the ”Sigcau family and the Xhosa people fortitude during this difficult time”. – Sapa