African National Congress (ANC) councillor Loyiso Nkohla has been expelled from the party following his involvement in faeces-dumping protests, Mail & Guardian has reported.
Nkohla and former councillor Andile Lili led protesters to deposit faeces on the steps of the Western Cape legislature and at Cape Town International Airport in 2013, as part of their protest for better sanitation services in townships.
The protesters accused the local government, run by Ms Zille's Democratic Alliance (DA), of not doing enough to provide proper housing and sanitation to townships.
The DA argued that it did not have the money to do this for all of the region's inhabitants.
Nkohla was serving out a three-year suspension from the party after he disrupted an ANC event in Cape Town where President Jacob Zuma was speaking.
"After his previous suspension, he failed to rehabilitate himself," committee chairperson Faizel Moosa said.
"The charges on which the respondents have been found guilty are of a very serious nature as it involved insubordination, insolent conduct and, very likely, criminality," the disciplinary committee said in its written judgment.
The fact that the two men continued their actions despite being informed by ANC leaders, even at national level, that their conduct would not be condoned, was seen as an aggravating factor.
"Both respondents did not display any remorse for their actions," the committee said.
"They pleaded not guilty on the basis that they have to answer to no one, particularly not the ANC, and maintained to the very end of the hearing that they have no accountability whatsoever to the ANC pertaining to their actions."
Both former councillors refused to apologise.
Nkohla insisted that he had not been fired from the party until "nation leadership expressed an opinion" and said he would meet with his legal counsel on what step to take next.
Lili was arrested and given a suspended three-year sentence, disqualifying him from participating in ANC activities for one year.
"We are emptying our toilets there because our toilets have smelled for three months," he told South Africa's Eyewitness News, after his arrest.
The government had provided portable toilets to some inhabitants, but protesters said they weren't good enough.
Lili added that the arrests would not put an end to their protests.
"This is a violation of a human's right to dignity. We have a right to dignity and we have a right to privacy.
"All those rights were violated by Helen Zille," he said.