Applications for leave to cross-examine witnesses are expected to be heard when the state capture commission of inquiry continues in Parktown, Johannesburg on Thursday.
"The legal team is in the process of identifying and/or consulting with other witnesses, who will be called to appear before the commission over the next few weeks," it said.
The commission, headed by Deputy Chief Justice Raymond Zondo, is expected to start at 10:00.
So far, five witnesses have testified.
On Monday and last Friday, GCIS acting CEO Phumla Williams implicated former communications minister Faith Muthambi at the inquiry, accusing her of wanting to "steal at all cost" from the Government Communication Information System.
Williams told the commission that Muthambi rendered GCIS dysfunctional during her short stay as minister and that she, at one point, appointed a junior to act as the director general, bypassing three deputy directors general.
She said Muthambi had also stripped her of 70% of her functions as deputy director general, including her responsibilities over supply chain management and finances.
Williams also said Muthambi wanted to oust her because she wanted someone that "they could manipulate" in charge of procurement and finances.
Following her testimony, Muthambi released a scathing statement lashing out at Williams and calling her a liar.
"Phumla Williams is one of the most shameful manipulators and liars that I have ever had the displeasure to encounter," Muthambi said in the statement.
"This is exactly the Phumla Williams I worked with, who couldn't pass the opportunity to tell a lie, any lie, to ingratiate herself with anyone in a position of authority and now panders to the most basest instincts of the public," she said.
The commission has heard that R55m was paid from GCIS to the Gupta-owned The New Age (TNA) newspaper when it sponsored the controversial SABC/TNA breakfasts.
It is investigating allegations of undue influence by the politically-connected Gupta family over former president Jacob Zuma's administration.