The EFF could not confirm a report that one of its members had given the party an ultimatum to declare its elective conference null and void as it was "undemocratic".
"I don't know anything about this matter," Economic Freedom Fighters acting spokesman Fana Mokoena said.
"I don't know if they have that letter. I called the leadership this morning and they haven't come back to me so I can't confirm this matter."
The Citizen newspaper reported that Mpho Ramakatsa wrote a letter addressed to the party's leader Julius Malema and all provincial secretaries, giving the EFF seven days to declare the conference null and void.
Ramakatsa, who was not elected to a top position, reportedly said the conference was an "undemocratic, unconstitutional and irregular gathering".
According to the newspaper, he wanted the party to reverse the elective conference results or else he would "seek recourse elsewhere".
The conference was held last month at the University of the Free State.