The judicial commission of inquiry into state capture is on Monday expected to hear evidence from representatives of banks that were involved in the closure of Gupta related bank accounts.
In 2016, the country's big four banks decided to close Gupta owned bank accounts after they detected several suspicious transactions.
So far, six witnesses have testified.
Last week, chairperson of the commission of inquiry Deputy Chief Justice Raymond Zondo invited former president Jacob Zuma to give his side of the story on allegations against him.
This was after evidence presented by former ANC MP Vytjie Mentor stated that Zuma was at the Guptas' home when she was offered a ministerial post.
Mentor told the commission that Ajay Gupta had offered her the job of public enterprises minister if she in turn would drop the SAA Johannesburg to Mumbai route so that a Gupta-linked company, Jet Airways, could benefit.
Former CEO of the Government Communication and Information System (GCIS) Themba Maseko also told the commission that Zuma had personally called him asking him to "help" the Guptas, who were looking to secure government advertising for their newspaper, The New Age.
Zondo also expressed concerns over the Gupta brothers' applications from abroad to cross-examine witnesses.
This was after Advocate Mike Hellens, SC, for Ajay Gupta, said his client was willing to testify and wanted to cross-examine witnesses from a location outside South Africa.
He said the commission doesn't have to send a "caravan" to Dubai, one person can go.
Hellens claimed that the Gupta brothers were worried about possibly being arrested if they returned to South Africa, labelling the Hawks and the National Prosecuting Authority (NPA) as "recklessly incompetent and a national embarrassment".
Hellens also told the commission that Ajay Gupta has a "powerfully contrary version" to former ANC MP Vytjie Mentor's version of events, that might not be put before the commission.
She said Ajay told her that there was a planned reshuffle by former president Jacob Zuma and he was going to fire Barbara Hogan, who was the incumbent.
Former deputy finance minister Mcebisi Jonas also claimed the Guptas offered him R600m if he accepted the finance minister post.