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Since Deputy President Cyril Ramaphosa was elected party leader in December, Zuma has faced mounting calls from his party to end his scandal-plagued second term due to run out mid-2019.
The party's executive committee has the authority to order Zuma to step down as head of state, although there is domestic media speculation that he might refuse.
"We decided to recall Zuma. He hasn't been told yet," the senior ANC source said.
"Cyril went to speak with him," the source said, adding that when Ramaphosa returned, "the discussions were tense and difficult on whether to recall Zuma."
ANC officials and Zuma's spokesman could not be reached for comment.
When Ramaphosa went to meet Zuma, the SABC state broadcaster, citing sources, reported that the ANC's executive group had given Zuma 48 hours to resign as head of state.
Zuma's tenure as president officially runs until mid-2019 and he has not said in public whether he will step down voluntarily.
Since becoming president in 2009, Zuma has been dogged by scandal.
Ramaphosa has put the focus on rooting out corruption and revitalising economic growth since defeating Zuma's preferred successor, Zuma's ex-wife Nkosazana Dlamini-Zuma, in the ANC leadership race.