South African elite police unit Hawks on Wednesday arrested three people and two other suspects are expected to hand themselves in after raids on various properties in Johannesburg.
The raid were part of a wider corruption probe, spokesman Hangwani Mulaudzi said.
The raided properties include the family compound of the Gupta brothers, businessmen friends of President Jacob Zuma.
The police are expected to arrest between five and seven more people as part of the raids, a senior judicial source said.
The source, who has knowledge of police moves and intentions, told Reuters there were no plans as yet to arrest cabinet ministers who have been linked in the media to the Guptas.
Zuma and the Guptas have denied any wrongdoing.