Eskom continues to be the focus of the Zondo Commission of Inquiry into State Capture as it resumes on Tuesday.
Gert Opperman, a coal supply unit manager at Eskom, told the inquiry on Monday that former acting Eskom boss Matshela Koko allegedly used his influence to lobby the utility's Majuba power station to accept substandard coal from the Gupta's Brakfontein mine.
Opperman, who managed Eskom's coal supply contract with the Brakfontein mine -owned by the Gupta family's Tegeta Exploration and Resources - told the commission that after he rejected a consignment of coal in 2015, Koko called him directly and asked him to reverse his decision.
On Tuesday the inquiry will hear the Eskom-related testimony of Johann Bester.
Standard Bank's head of compliance Ian Sinton and former business rescue practitioner of Optimum coal mine Piers Marsden are also expected to testify.
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