Johannesburg - A National Treasury official is expected to testify at the state capture inquiry on Monday morning.
Jan Gilliland from the National Treasury is expected to give details of payments made to the controversial Gupta family.
Last week the inquiry heard testimony from the acting director-general of the government communication and information systems (GCIS) Phumla Williams.
Williams gave a chilling testimony of how former communications minister Faith Muthambi wanted to "steal at all costs".
Williams said Muthambi's reign as the minister of communications had a devastating effect on the GCIS and that many crucial posts remained unfilled for months with Muthambi refusing to fill the posts.
"Many people had to double-up in their functions. Many offices around the country remained unfilled because she refused to fill those posts," said Williams.
In 2016, Muthambi stripped Williams of 72% of her responsibilities, which included that all her managing roles were then directed to the then acting GCIS director general Donald Diphoko at the time.
Williams also told the inquiry how her predecessor Mzwanele Manyi took control of GCIS' media buying unit, the tender board and appointed new members of the board.
GCIS procurement officials were bullied into funding The New Age business breakfast briefings which were run by the Gupta family's newspaper in partnership with the SABC, said Williams.
Former GCIS CEO Themba Maseko had also testified and detailed how he was fired from his job after he refused to assist the Gupta family gain access to the GCIS's media buying budget. His firing was pushed by former president Jacob Zuma, a close friend of the Gupta family who then ensured the hiring of Manyi to replace Maseko.
This week, deputy chief justice Raymond Zondo, the head of the commission, is expected to rule on whether to allow Rajesh Gupta, Ajay Gupta, and Duduzane Zuma's applications to cross-examine witnesses.
The brothers' legal representatives argued last week that they were willing to testify at the inquiry, but were unwilling to come back to South African and were only willing to testify via video link.
Duduzane's legal representative told Zondo that he was facing a parallel legal process and was unable to testify at the inquiry. He is facing charges linked to the bribing of former deputy finance minister Mcebisi Jonas.