On March 2, Ngubane called a special meeting with the intention of suspending Koko. It started at 6pm, but seconds later Brown phoned Ngubane and ordered him not to go ahead, said a source who was at the meeting.

"Koko was summoned to be served with a letter of intention to suspend him but was told to wait outside as Ngubane first wanted to inform the board why he had called the meeting," the source said. "The minister called him out of the blue and ordered him not to do it."

Another source said one board member was later overheard boasting that he had phoned the Guptas to warn them.

"It is alleged that the Guptas then phoned the minister and asked her to stop Ngubane from suspending Koko, who was their eyes and ears at Eskom," the source said.

According to two separate investigations, Koko allegedly leaked Eskom legal opinions to the Guptas and arranged a R659-million prepayment for their company Tegeta Exploration and Resources.

Leaked Guptas e-mails reveal that the controversial family once flew Koko to Dubai and spent R11,500 on his accommodation.