National Freedom Party (NFP) leader Zanele kaMagwaza-Msibi died in hospital on Monday, the party confirmed.
NFP MP Ahmed Shaik Emam said the party was reeling from the news.
He said kaMagwaza-Msibi had been admitted to an Umhlanga hospital in Durban.
KaMagwaza-Msibi, a former deputy minister, cited ill health when she resigned from Parliament in 2019.
Ahmed Munzoor Shaik-Emam, NFP parliamentary caucus leader, told iReport SA Newson Monday that Magwaza-Msibi, 59, had been ill and was admitted to a Durban hospital.
“She was in the ICU for some time and unfortunately she succumbed to her illness on Monday morning. The party is left grieving her loss and our thoughts and prayers are with her family at this time.
“She was an inspirational leader, who despite suffering a massive stroke in 2014 continued with her work, despite her health challenges,” he said.
Shaik-Emam said they would liaise with the family with regard to providing the necessary support at this time.
In a statement, family spokesperson Canaan Mdletshe confirmed that Magwaza-Msibi had suffered a cardiac arrest.
“Ms Magwaza-Msibi was an exemplary leader, an activist and an advocate of our democracy. She lived her life fighting and championing the cause of the poor, vulnerable and downtrodden. She was a loved and greatly respected leader, whose passing leaves many at a loss.”
He said funeral details were being confirmed.
Magwaza-Msibi served as a deputy minister of science and technology under former president Jacob Zuma.
She was a long-standing member of the IFP before founding the NFP.