President Kgalema Motlanthe's wife claims she is not aware of her husband's alleged extra-marital affairs.
The Sunday Independent on Sunday revealed Motlanthe's relationships with two other women, one of whom is allegedly carrying his child.
Gugu Mtshali, 45, who works at ANC headquarters, divorced her husband of 17 years in December 2008 to continue her long-time relationship with Motlanthe, although the pair continue to live apart.
Meanwhile, Lebo Makoe, 24, is alleged to be heavily pregnant with Motlanthe's child, something she has flatly denied.
Motlanthe has declined to comment on his involvement with either of the two women.
However, on Sunday afternoon his wife and mother of his three children - Mapula - was not aware of the weekend expose.
"Is my husband involved with somebody?," she asked when tracked down at her Blue Valley home, a house the family shared until the President relocated to Mahlambandlopfu.
"It's okay. It's not a problem," she said in a dignified manner when the contents of the story were put to her.
She declined to comment further.
However, the ANC has dismissed the story as a smear campaign against Motlanthe, which comes at a time when the party is putting the finishing touches to its election lists amid rumours that Motlanthe may not return to government after the poll.
Party spokesperson Carl Niehaus said it is no more than "an anonymous smear", saying the ANC would issue a statement on Monday to reaffirm their support for him.
He said Motlanthe had repeatedly said his private life was his own and that he was entitled to keep it that way.
The DA agrees with the ruling party, saying regardless of whether it is a first spouse or not, "a person's private life should be respected", according to party spokesperson Paul Boughey.
COPE, on the other hand, makes the point that the spousal office in the Presidency is funded by taxpayers' money and that the public have a right to know who the first lady of the country is.
"Zanele Mbeki ran the very successful Women in Dialogue programme from it during her day," JJ Tabane said.
"The role of the first spouse is very important and it is only natural that people want to know who the first lady is."
The ANC and the Presidency have closed ranks on the matter, declining to reveal anything about who she might be.
However, after a week-long investigation, it has been learnt that Motlanthe and Mtshali have been intimately involved for a number of years and that it was because of the relationship that Mtshali left her Sydenham home in August 2008 and finally divorced from her husband in December.
She now lives in Norwood and continues to work at Luthuli House where she is personal assistant to Mathews Phosa.
Unbeknown to Mtshali and to Mapula Motlanthe, Makoe has also spent time at the President's side and has confided to close family members and friends that she is carrying his child.
Although she has denied any intimate involvement with him, her comments on the matter raise questions about her involvement with the man who is running the country.
"The story is not just going to damage Kgalema's image, it's also going to damage mine because I'm also involved in it," she said when she was informed that their alleged relationship would be exposed.
"It's going to cause a lot of havoc, for me especially."
"I'm not the public figure. Kgalema is the public figure," she continued.
"And it's not for me to be dragged into this story just because some people feel they want to know who he's dating and what he's doing and when he's doing it.
"Really, it puts me in a very awkward position."
Late on Friday evening she claimed to be acting on the instructions of Motlanthe's advisers when she declined to give further comment.
"I called the Presidency and they said no, I mustn't give out any comments," she said, yet failed once again to explain why the Presidency would extend advice to her if she had no relation with it or Motlanthe in any way.