Eskom chairperson Jabu Mabuza told the Zondo Inquiry on Monday that former acting chief executive, Matshela Koko, leaked confidential documents to third party companies that wanted to do consulting business with Eskom.

Resuming his testimony on Monday, Mabuza reiterated his allegation that emails retrieved from Koko's server show that Eskom's confidential documents were, in 2015, sent to the email address which was linked to Salim Essa, believed to be an associate of the notorious Gupta family.

A report by Advocate Geoff Budlender found that Eskom had illegally paid R250-million to Essa's company, Trillian Holdings, for consultancy work which had not been tendered for and for which there was no formal contract with Eskom.  

Mabuza said one of the emails contained a document from National Treasury on how government departments should contain their costs.

Another email that Koko allegedly sent to Essa had an attachment with information on a programme to invest in top engineers while another had internal Eskom consulting directives. 

The Top Engineers Programme was the idea of the previous executive committee compiled in 2014. 

Mabuza said Koko gave this confidential information to help Essa and his associates gain an unfair advantage to know how to go about bidding to offer these services, and that this was used in 2015 in order for Eskom to enter into contract with Trillian and McKinsey.

"The intention was never to comply. The intention was to create opportunities for specific people with specific objectives," Mabuza said.

An email was also sent from Koko's work email to Essa informing him about some executive committee resolutions on the round robin at Eskom.

Koko resigned from Eskom in February 2018, hours before a second disciplinary hearing, instituted by the new board, could be heard.

On Friday, Mabuza detailed charges leveled against Koko and other former executives, among them former chief financial officer Anoj Singh. 

Mabuza told the commission that the present board of directors discovered that the power utility was "the main stage in the theatre of corruption" when it was appointed in January 2018.

Mabuza was set to continue his testimony after a tea-break adjournment.