Public Protector Busisiwe Mkhwebane has dismissed the institution's chief operating officer, Basani Baloyi, and suspended four senior officials and investigators.
Baloyi will leave the Public Protector's employ at the end of this month.
Executive manager Pona Mogaladi, chief investigator Abongile Madiba, chief investigator Lesedi Sekele and senior investigator Tebogo Kekana have been suspended, News24 has confirmed.
It is unclear which investigations they were involved in, but it is understood at least one of them was involved in a complaint EFF leader Julius Malema lodged against the Financial Services Conduct Authority. That report is being reviewed in the High Court.
In a letter penned by the Public Protector's chief executive Vussy Mahlangu, which News24 has seen, Baloyi is deemed unsuitable for the position of chief operating officer, lacking the required skills and conduct.
Mahlangu said in the letter that the Public Protector could not make Baloyi a permanent employee, adding that if she wished to appeal the decision, she should do so directly to Mkhwebane.
Baloyi will not be required to work for the rest of the month but must be available if needed.
Mkhwebane is under political pressure after a series of court defeats related to her pursuit of President Cyril Ramaphosa and Public Enterprises Minister Pravin Gordhan.
Parliament will also take a decision soon on an inquiry into her fitness for office.
Public Protector spokesperson Oupa Segalwe has been approached for comment. This story will be updated once it is received.
This is a developing story.