A vehicle believed to be that of ANC secretary-general Ace Magashule and his deputy, Jessie Duarte, was spotted at President Jacob Zuma's official residence Mahlamba Ndlopfu on Tuesday.
A motorcade arrived at around 09:20 and was inside the premises for about an hour.
The ANC national executive committee (NEC) was expected to write to Zuma on Tuesday morning, informing him of its decision to recall him. It was not immediately clear if Magashule and Duarte were delivering the letter of recall to Zuma.
There has been no sighting of Zuma and it appears to be business as usual at the residence with police, military and other vehicles driving in and out.
Shortly after noon, a motorcade of five vehicles left the residence.
Journalists were camped outside the residence.
On Sunday ANC president Cyril Ramaphosa announced, in his address at the launch of the ANC's Nelson Mandela centenary celebration in Cape Town, that the matter involving Zuma would be resolved at an NEC meeting.
The ANC NEC held a 13-hour-long meeting in Irene, outside Pretoria, which started at 14:00 on Monday and ended at 03:00 on Tuesday.
At 23:00, the NEC instructed Ramaphosa and Magashule to drive to Mahlamba Ndlopfu in Pretoria to give Zuma an ultimatum to resign or face a recall.
That meeting lasted less than an hour, with Zuma refusing to comply.
Motion of no confidence
Ramaphosa and Magashule delivered that news to the NEC meeting at 00:00. The hotel was on lockdown in the hour that the two left to meet Zuma and returned.
The ANC is expected to brief the media at Luthuli House at 14:00 on Tuesday.
Meanwhile in Parliament, the EFF extended its deadline to National Assembly Speaker Baleka Mbete for a decision on the House hearing the motion of no confidence against Zuma to Tuesday at 13:00.
Their initial deadline was 10:00 on Tuesday, and EFF leader Julius Malema said the party would go to court if this deadline was not met.
The motion is scheduled for February 22, but opposition parties agreed that they want it heard this week. They also said on Monday that they would bring a motion to dissolve the National Assembly once the motion of no confidence is heard.
An urgent meeting for the chief whips of all the parties in Parliament has been scheduled for Wednesday at 08:00, followed by a meeting of the ANC caucus at 10:00.