The African National Congress's (ANC's) national working committee (NWC) has rejected a report from its Eastern Cape branch into its "festival of chairs" conference and some have described it as biased, sources have said.

NWC members met on Monday to discuss the report into last year's provincial conference that descended into chaos when party members threw chairs at each other, leaving scores of delegates injured.

The ANC's national executive committee (NEC) tasked Sbu Ndebele with investigating the legitimacy of the conference, after disputes were lodged with the party's highest decision-making body between conferences. The other members of the panel were Rejoice Mabudafhasi, Joyce Moloi Moropa and Sdumo Dlamini.

"The report was not factual," an NWC member, who did not want to be named, told News24.

He said there were objections to some of the elements in the report, including that there were no threats of violence before the conference got under way.

Another member close to the matter said the NWC felt that the report did not correctly reflect what had happened that night and was it comprised.

"Parts of the report showed a level of bias," he said.

The Eastern Cape's July conference elected Oscar Mabuyane to replace Premier Phumulo Masualle as chair of the party's third-biggest province. It was marred by deep divisions between the two factions.

A purported leaked report recommended that an interim structure be appointed to lead the province to fresh elections within three months. It recommended that the provincial task team should include both warring factions.

Masualle's faction took the outcome of the conference to court and lost in the Eastern Cape High Court in East London.

News24 understands the disgruntled members have taken the case to the Constitutional Court. They argue that, while credentials were being adopted, some members left the conference following the violence.

"We said the court case course must in the meantime go on," another NWC member said.

The worry within the party is that, if the election of the Eastern Cape executive committee members is nullified, it could have potentially negative implications on the national elective conference at Nasrec, that elected Cyril Ramaphosa to replace Jacob Zuma as party president.

It would mean the 35 PEC members were not legitimately at the conference as they were not properly elected.

"It would mean that those who are mischievous could easily challenge [the] Nasrec conference in court on [the] basis of [the] credentials of the PEC members and the NWC as well, as the NEC knows this," a provincial leader told News24.

The NWC also discussed disputes surrounding the Free State provincial task team.

Disgruntled Free State members marched on Luthuli House last week, demanding that it be dissolved.

They have accused secretary general Ace Magashule, the former chair of the Free State, of appointing people close to him in the provincial task team.

Some of the members were elected at the nullified December conference.

It is understood that Magashule was advised to get legal advice on the matter.