Yesterday sources revealed that Nompumelelo MaNtuli-Zuma's affair with actor Joe Mafela produced a son. The boy is 13.
MaNtuli, who travelled with the president last week, has gone to ground. Yesterday her phone went unanswered the whole day.
But Mafela, 67, revealed in an interview with the Sunday Times that he had had an affair with MaNtuli, 35, before she met Zuma.
"Where do I start explaining this to my wife and children? I don't want to tear my family apart. The matter is very sensitive. These things happened years ago before she even met the president. I don't want to be in the president's bad books," Mafela told the Sunday Times.
Mafela is best known for his role as S'dumo in the 1980s television sitcom Sgudi Snaysi.
The scandal broke last week when Ilanga newspaper published a story about an affair involving MaNtuli and her bodyguard, named as Phinda Thomo. The paper claimed Zuma's family, fed up with MaNtuli's "bad behaviour", had exposed the infidelity because Zuma was not acting.
The story also cast doubt on the paternity of MaNtuli's unborn child. She and Zuma have been married since 2008. MaNtuli is also a mother to Zuma's eight-year-old daughter Thandisiwe and Sinqobile, 4.
Thomo, of Dobsonville, Soweto, allegedly committed suicide when news of the affair became public.
Zuma told journalists in Pretoria yesterday: "We differentiate between personal matters and matters of the country."
On Friday the presidency issued a statement accusing the media of "undermining" Zuma and his family's right to privacy and dignity.