It came a day after the secretary general of Mr Zuma's ruling African National Congress, Ace Magashule, said the president would host a 10am (local time) briefing the following day in response to the call for him to resign amid corruption allegations.
Mr Zuma's grip on power began to erode when Cyril Ramaphosa narrowly won the ANC's elective conference in December and was chosen to become the party's new president.
Since then even some members of his inner circle have joined the call for him to step down.
Malusi Gigaba, the minister of finance and a close ally of Mr Zuma's, told CNN on Tuesday night that the president was expected to "do the right thing" and step down.
"Should he refuse, we would have to resort to a parliamentary process, with a 62 per cent majority, with the support of other opposition parties, we are certain it will pass," Mr Gigaba said.
Mr Magashule, who was also a staunch Zuma supporter, has shifted his public stance from personal loyalty to party unity.
"The decision of the NEC [National Executive Committee] is now final," he told reporters on Tuesday. "We said comrade Ramaphosa must become the president of the ANC."
Meanwhile, other Zuma supporters are having problems of their own.
On Wednesday morning, the country's anti-corruption task force, The Hawks, raided the Saxonwold compound of the Gupta family — three brothers whose business affairs have become inextricably bound with those of Mr Zuma.
State broadcaster SABC said that three people, including one of the Guptas, had been arrested, and that Mr Zuma's son, Duduzane, a business associate of the Guptas was also being sought.
Later, however, a lawyer representing the family told Reuters that none of the brothers had been arrested and that the media had "got it wrong".
Originally from India, the Guptas became part of Mr Zuma's inner circle, to the point where they were reportedly hiring and firing government ministers.
Hangwani Mulaudzi, a spokesman for The Hawks, said the raid was part of an investigation into allegations of influence-peddling in the government.
Mr Mulaudzi did not confirm or deny the arrests, but said the investigation was in full swing, including the raid on the Gupta property. More arrests are expected.
“We’re viewing this investigation in a very serious light. We’re not playing around in terms of making sure that those who are responsible in the so-called state capture, they take responsibility for it,” Mr Mulaudzi said.