Zuma's appearance at the public inquiry into state corruption - set up to test allegations that Zuma allowed cronies to plunder state resources and influence government appointments - marked a dramatic fall from grace for a politician who dominated the country's politics for the past decade.

Zuma, ousted by the governing African National Congress (ANC) in February 2018 and replaced by President Cyril Ramaphosa, has consistently denied wrongdoing over his nine years in power.

"I've been vilified, alleged to be the king of corrupt people," Zuma said in his opening remarks, looking relaxed and wearing a dark suit and a red tie.

"This commission, from my understanding, was really created to have me coming here, and perhaps to find things on me," he added. "There has been a drive to remove me from the scene, ... a conspiracy against me."

A group of several dozen supporters broke into clapping and chants of "Zuma" as the former president entered the room where the inquiry was being held in Johannesburg.

Zuma's son Duduzane and ally Des van Rooyen, whom Zuma appointed finance minister in 2015 before reversing the decision days later as financial markets tanked, were among those supporting the former president.

On Sunday, Zuma made fun of his opponents in a video posted on Twitter in which he laughed and danced while chanting "Zuma must fall", a slogan used by protesters demanding he step down several years ago.

He is expected to give evidence from Monday to Friday in testimony that will be broadcast live on South African television. It is a rare example of an African leader being brought to book soon after losing power.

Zuma, 77, has also been in court on several occasions over the past year to answer corruption charges linked to a deal to buy military hardware for the armed forces in the 1990s.

Under pressure from rivals in the ANC, Zuma set up the corruption inquiry he now sits before in his final weeks as president, as a number of his colleagues, including Ramaphosa, feared scandals surrounding Zuma could indelibly tarnish the party's reputation.

The inquiry, headed by South Africa's deputy chief justice, Raymond Zondo, held its first hearing in August and is due to finish next year.

Zuma had avoided establishing the inquiry since a 2016 report by the country's anti-corruption watchdog, the public protector, instructed him to do so to investigate allegations that three brothers had been able to influence ministerial appointments and had won state contracts improperly.

The Gupta family, business friends of Zuma, denied the accusations and left South Africa around the time that Zuma was ousted.

Ramaphosa, Zuma's former deputy, has made sweeping personnel changes in government and state-owned companies as part of an effort to curb corruption and revive the stagnant economy.

Australian Associated Press