SABC radio and television presenter Vuyo Mbuli died of a pulmonary embolism, the broadcaster reported on Tuesday.
It reported that this was the outcome of a post mortem conducted on Monday.
Previous reports that Mbuli suffered a heart attack were untrue, family spokeswoman Rowena Baird told the SABC.
“His blood had clotted and he had two relatively large clots,” she told the broadcaster.
“The clots tend to move around the body, and they moved to his chest, hence he complained of chest pains.”
Mbuli, 46, collapsed while watching the Cheetahs' 27-13 Vodacom Super Rugby win over the Reds at the Free State Stadium on Saturday night.
He was treated on the scene before being taken to the Mediclinic hospital in Bloemfontein, where he died. - Sapa