Ajay Gupta revealed top secret information regarding state-owned arms manufacturer Denel during a meeting at the family's Saxonwold compound, former African National Congress (ANC) parliamentarian Vytjie Mentor testified at the state capture commission of inquiry on Tuesday.
This was a meeting that Mentor testified she was called to at the time when she headed Parliament's Portfolio Committee on Public Enterprises in 2010.
She had been requesting to meet former President Jacob Zuma but ended up meeting with Ajay Gupta in Saxonwold.
At the meeting, Gupta offered her a promotion to become public enterprise minister in place of the then incumbent Barbara Hogan - that was if she agreed to cancel South Africa Airways' Mumbai, India route. Mentor testified that Zuma was in the next room when the offer was made.
The former ANC MP said she was shocked at Gupta's revelations about Denel.
''He brought forward the issue of Denel, he mentioned a specific matter that was between Denel and some companies in India and the Indian government," revealed Mentor.
"That issue was a top-secret matter that no private citizen should have known about...I was a member of the joint standing committee on intelligence and knew about that matter but never said much about it.
"I do not want to disclose much about that here, but Gupta said there was something regarding that matter that he wanted to resolve for Denel and the Indian government,'' Mentor said.
She said because the Denel matter was top secret, she opted not to talk to Gupta about it any further.
Mentor said when she decided to leave, as she was agitated by Gupta, Zuma emerged from the next room in the house.
She said all Zuma did was try to calm her down in isiZulu, telling her everything would be alright and she should not to worry.
Gupta then asked Zuma if he wanted to eat anything, and spoke to him in a demeaning manner, said Mentor.
''I felt that the [former] president would not attend to the agenda I wanted to meet him for, so I left. As we were leaving, Ajay asked him 'what do you want to eat' in a disrespectful manner," said Mentor.
"Firstly, Ajay did not rise to his feet when the president entered the room, and secondly, that is not how you speak to a president when offering him food. The president replied and said he was going to 'eat next door', he said his son Duduzane lived next door.''
Earlier, commission chairman deputy chief justice Raymond Zondo ruled on applications by lawyers of those implicated at the commission so far to cross-examine witnesses.
Zondo said he intends to grant cross-examinations but with a time limit. Legal representatives of businessman Fana Hlangwane, Hawks top official Major General Zintle Mnonopi and former Zuma aide Lakela Kaunda are to file more papers by Friday and clarify further on their evidence.
Mike Hellens, representing Ajay Gupta, indicated he wanted to cross-examine and would also lodge his application by Friday. Zuma's legal representatives were still to announce whether they would want to cross-examine.