Democratic Alliance (DA) member Helen Zille could face expulsion over comments she made in defence of colonialism. Zille reportedly faces the DA's internal structures for a preliminary probe into the comments.
Party leaders who spoke to Business Day said the former party head would face the "harshest possible sanction" if found guilty.
DA federal executive chair, James Selfe, told the paper that Zille would face the DA's federal legal commission (FLC) on Saturday.
Business Day reported on Thursday that FLC chair Glynnis Breytenbach said a report would be sent to the federal executive once the probe was complete, and only then would a decision be taken on whether or not to charge Zille.
If she is charged, the federal commission will decide on a sanction, which must then be ratified by the federal executive, Breytenbach told Business Day.
DA leader Mmusi Maimane told the paper that the DA had been built on institutions, and that no one was bigger than the party.
"... because the organisation is made up of South Africans who are from different walks of life, subjecting themselves to the same values and the same institutional capacity," he reportedly said.
Meanwhile, Zille's comments will be debated in the Western Cape provincial legislature next week, The Times reported.