Two people have been arrested in a raid on the home of the controversial Gupta family in South Africa as part of a government influencing investigation.
The wealthy India-born Gupta family have been accused of "state capture" - using their friendship with President Zuma to wield enormous political influence for their business interests.
Both Mr Zuma and the Guptas deny the allegations made against them.
Mr Zuma is under pressure to resign, in part because of links to the Guptas.
The Hawks, South Africa's priority crime unit, confirmed they were searching the Gupta's walled compound near Johannesburg zoo on Wednesday morning.
Local media say that one of the three Gupta brothers has been arrested but the BBC has so far been unable to confirm this.
The scandal-hit leader has been in power since 2009, but has been dogged by corruption allegations.
Mr Zuma was replaced as the party's leader in December by his deputy, Cyril Ramaphosa, but has so far resisted calls to resign.
An official has said the 75-year-old was willing to stand down in the next three to six months, but top leadership want him to withdraw from power immediately.
The embattled Gupta family own a range of business interests in South Africa, including computing, mining, air travel, energy, technology and media.
The three brothers, Atul, Rajesh and Ajay, moved to the country in 1993 from India, just as white-minority rule was ending.
They are known friends of President Zuma - and his son, daughter and one of the president's wives worked for the family's firms.
The brothers have been accused of wielding enormous political influence in South Africa, with critics alleging that they have tried to "capture the state" to advance their own business interests.
Former Deputy Finance Minister Mcebisi Jonas made a public allegation in 2016 that he was offered 600m Rand ($50m; £36m) by the Gupta family to be the next finance minister - as long as he did their bidding.
The public backlash worsened in 2017 when more than 100,000 emails were leaked which appeared to show the extent the family had exerted their influence.
It suggested a complex web of government contracts, as well as alleged kickbacks and money laundering.
It prompted marches and public protests against the family and President Zuma, dubbed the "Zuptas".