The Presidency had initially planned to hold a media briefing for President Jacob Zuma at the Union Building at 10:00 on Wednesday, but the request was later withdrawn, an official email shows.
Media24 titles have seen an email sent by Presidency deputy director of communications Shadi Baloyi at 16:39 on Tuesday, requesting the SAPS permit office allow media vans on the Union Buildings premises at 10:00.
"We will share details as we are yet to release the approved media release," Baloyi said.
However at 22:26 on Tuesday, Baloyi cancelled the request.
News24's Alex Mitchley, who is stationed outside the Union Buildings, says security showed journalists the same email chain when informing them the briefing was cancelled.
Baloyi on Wednesday issued an official statement that "no official communication" had been issued by the Presidency on a media briefing on Wednesday by President Jacob Zuma, as reported by media houses.
"The media is urged to await official notification," she said.
Finance Minister Malusi Gigaba however told CNN on Tuesday that Zuma was expected to announce his resignation at 10:00.
The African National Congress caucus moved back its meeting as a result, he told the broadcaster.
If he did not resign, the caucus would vote to remove him through a scheduled motion of no confidence, Gigaba said.