Zambia's ruling Patriotic Front (PF) has suspended President Guy Scott as party leader amid a power struggle ahead of elections in January.
The party's central committee accused him of "unconstitutional conduct".
But state radio later quoted the PF secretary-general as saying the decision was invalid, as only Mr Scott could call a meeting of the committee.
Mr Scott, who took over after President Michael Sata died last month, remains interim president until the poll.
He cannot become substantive president because his parents were born abroad.
PF spokesman Malozo Sichone told the BBC that Mr Scott's suspension comes after party officials had spent weeks trying to meet the president to discuss the election and selection process.
"Since the president's death, it has become clear that Dr Scott has been following his own agenda," said Mr Sichone.
"He has been hiring and firing people for no apparent reason and without consulting the [party's] central committee," he said.
The party is divided over how its presidential candidate at the next election should be selected, with some calling for the 53-member central committee to choose.
Mr Scott and other MPs want a vote by a general conference, made up of thousands of delegates.
Mr Scott lost favour with many members of the party after he sacked presidential hopeful, Edgar Lungu from his post as PF secretary-general without any explanation.
Mr Lungu was re-hired a day later following protests from his supporters in the capital, Lusaka.
He has said he is on a leave of absence from the position while the party decides who will contest the election. Meanwhile, Bridget Atanga has been appointed PF secretary-general.
Correspondents say the reinstatement has done little to win back protesters' trust, as some within the party suspect Mr Scott may have his own candidate in mind for the presidential nomination.
Mr Lungu had been named acting president when Mr Sata sought medical treatment in London and is seen as a frontrunner in the elections.
Mr Sata's son, Mulenga Sata, who is the mayor of Lusaka, and his widow, Christine Kaseba, have also said they will seek the PF's nomination, reports Reuters news agency.
Mr Scott, whose parents were British, is the first white head of state in mainland Africa for 20 years.