The Public Investment Corporation (PIC) suspended its acting chief executive on Tuesday over alleged interference in an inquiry into impropriety at the R2 trillion fund.

The PIC, one of the largest fund managers in Africa, said in a statement that it had placed acting CEO Matshepo More on a "precautionary suspension" and that Vuyani Hako, executive head of properties, had been appointed in her place.

More did not respond to a request for comment on her suspension, which comes several weeks after the PIC's board of directors tendered its resignation because of allegations of wrongdoing by four directors.

It was not immediately clear how More is alleged to have interfered with the judicial inquiry into the PIC, which President Cyril Ramaphosa authorised following allegations that some directors had used their position for personal gain.

A spokesman for the PIC said he could not elaborate.

The PIC is the largest investor on the Johannesburg Stock Exchange (JSE) with significant stakes in South African blue-chip firms as well as bonds of state-owned enterprises like struggling power firm Eskom and arms company Denel.

Finance Minister Tito Mboweni is yet to appoint a new board at the PIC, which this year suspended its head of listed investments and an assistant portfolio manager for allegedly breaking governance rules over a technology deal.