Lawyers for President Jacob Zuma on Tuesday made a High Court challenge to the setting up of a commission to examine corruption allegations.
Ishmael Semenya told the court in Pretoria that former Public Protector Thuli Madonsela had overstepped her powers in ordering the president to set up a commission of inquiry led by a judge appointed by the chief justice.
The case relates to claims that Zuma was influenced by the wealthy Gupta family to appoint and dismiss ministers in accordance with their interests or to secure lucrative government contracts.
The Guptas, whose interests include mining and media companies, are being investigated in South Africa over the appropriation of public money, known as "state capture". They are also reportedly under investigation by the FBI.
The three Gupta brothers, who reportedly relocated to South Africa from India in 1993, and Zuma have denied any wrong-doing.
Semenya said Madonsela, who held office as an anti-corruption watchdog until October last year, had acted unconstitutionally in directing the president to establish a commission.
"The public protector cannot order remedial action based on suspicion," he said. "A full investigation was needed."
He further accused her of failing to complete her probe but Madonsela said the inquiry had run out of funding, leading to her recommending an independent commission.
Zuma's lawyer asked court to set aside the remedial action recommended by Madonsela, namely establishing a commission under a judge appointed by the chief justice rather than the president.
