Sonono Khoza has denied having a love child with President Jacob Zuma, according to The Sowetan.
Khoza is the daughter of soccer boss Irvin Khoza, a long-time friend of Zuma.
The public comment on the latest reports that President Jacob Zuma fathered his 20th child out of wedlock:
The Sunday Times earlier reported that 39-year-old Khoza gave birth to Thandekile Matina Zuma on October 8 - about three months before Zuma married for the fifth time.
"What baby are you talking about? I have two children. They are in school. These are people's lives. Let me be," Khoza apparently told the Sowetan.
Khoza reportedly said she is "a grown woman" and had "done nothing wrong".
"You (the media) have freedom of speech and I have the freedom to live my life," said Khoza, a banking executive.
The Sowetan quoted sources as confirming that she had taken her maternity leave a month earlier than scheduled because of a difficult pregnancy.