The Democratic Alliance wants Parliament to schedule an ad hoc committee to fully investigate the relations of "captured ministers and officials, the president and the Gupta family" as early as this week.
In a statement released on Sunday, the Democratic Alliance's Shadow Minister of Public Enterprises, Natasha Mazzone, cited fresh reports that she said "expose the depth of the governance failures of public entities under Minister of Public Enterprises Lynne Brown, and allegations of Gupta capture against her".
One of the reports was about former independent non-executive director of Transnet, Iqbal Sharma, and how he passed on the confidential agenda of Transnet's board acquisitions and disposals committee to the Guptas a week before a May 2014 meeting of the board, which hiked the cost of a locomotives tender that was expected to earn the Guptas R5.3-billion.
"This only adds to scandals at Eskom, Transnet, SAA, Denel - all benefiting the Guptas, and all on Brown's watch. Brown must urgently suspend Seleke pending the ad hoc committee investigation," she said.
She said the DA was also looking at adding to criminal charges laid on 30 May based on Sunday's reports.
The call comes after ANC secretary general Gwede Mantashe was quoted by the Sunday Times saying the party wants President Jacob Zuma and all other living South African presidents since 1994 to testify in the yet to be set up judicial commission of inquiry into state capture.
"We want to know: Is the private sector influencing decisions in government and has government worked as its agent?" he told the paper.
ANC spokesperson Zizi Kodwa told the Sunday Times that while party called for the scope and terms of reference of the inquiry to be broadened, it could not be a generalised exercise.
"You see you can't create a commission of inquiry to be a circus. It has to be specific. You got to [sic] make the allegations [against the Guptas] as a reference point... those allegations in the public protector's report," he told the paper.