South African Public Protector Thuli Madonsela's last report, on the president's ties with the Gupta family, is being kept safe until her successor assumes office on Monday.

South Africa's ruling African National Congress (ANC) said on Saturday a report by an anti-graft watchdog into allegations of political interference by friends of President Jacob Zuma was being held at parliament for safekeeping.

The release of the potentially explosive report, which the outgoing head of the agency Thuli Madonsela had planned to make public on her last day in office on Friday, was delayed because of a court application by Zuma asking that it remain under wraps so he could review evidence and question witnesses.

The ANC said in a statement the report had been handed to parliament and would be given to the new Public Protector, Busisiwe Mkhwebane, on Monday when she assumes office. "The report, as requested, is currently being kept under lock and key in parliament," the ANC said.

The report looked at the alleged influence of the wealthy, Indian-born Gupta family – close friends of Zuma – regarding the appointment of cabinet ministers and other occupants of high office. Madonsela had announced the probe in June.

The family, which has wide-ranging business interests in South Africa, and the president have denied any wrongdoing.

The report comes at a time when Zuma's government is reeling after prosecutors this week ordered Finance Minister Pravin Gordhan to appear in court on November 2 to hear fraud charges against him. Gordhan on Friday dismissed the charges as "frivolous".

Madonsela interviewed Gordhan, former finance minister Nhlanhla Nene and deputy finance minister Mcebisi Jonas as part of the probe on Zuma's links with the Guptas, local media said.

In March this year Jonas said the Guptas had offered him Nene's job, an allegation that led to calls for Zuma to resign.

Madonsela has become something of a folk hero in South Africa for her fearless investigations of the rich and powerful and won public support for taking Zuma to task over the $16 million of state money spent upgrading his private home in Nkandla.