Eskom has denied that it was running out of coal ahead of winter and has said that a "mitigating strategy is in place".
Fin24 on Sunday reported that the power utility last week had to inform the National Energy Regulator of SA (Nersa) that coal stocks at seven of its power stations had dropped below the minimum level of 20 days' supply.
Eskom spokesperson Khulu Phasiwe confirmed to HuffPost that "seven power stations have low coal stockpiles".
"What we are doing as a mitigating strategy is to divert coal from the eight other power stations that have a surplus so that we can keep the system running. We are also in the process of signing new contracts with supplementary suppliers so we can continue to get coal into these power stations," Phasiwe said.
Eskom has also slammed reports that the power utility is considering bailing out the embattled Gupta-owned Optimum coal mine by accepting their request to double the rate charged for their coal.
Reports at the weekend suggested that the cash-strapped mine wants to more than double its rate per ton of coal to Eskom from R200 to R450, while cutting its total monthly supply to the parastatal in half.
Eskom spokesperson Khulu Phasiwe said the utility was "not prepared to do that".
"These reports which suggest that Eskom is willing to pay this amount, I don't know where they are coming from and the way these stories are written is as if Eskom is seriously considering this. Eskom is not in any way prepared to negotiate any of these prices," he told HuffPost on Monday.
"If we do that, Eskom will probably be shooting itself in the foot. The previous owners of that mine, which is Glencore, were asking for the same adjustment that Tegeta is asking for. So, if Eskom was to accede to their request, we will be falling into the trap that has already been set for us."
He said Eskom is in discussion with Optimum's business rescue practitioner, but no deal has been struck.
"People are saying Eskom has been bending backwards to accommodate the Guptas. If we were to do something like that [accept the deal], we would be falling into that trap... For us, the main aim really is to ensure that whatever is going to happen to this asset (Optimum), we are not going to be compromised in terms of the coal, the coal quality and the volume we have agreed on," he said.
"Whatever is going to happen, we are saying we are not going to negotiate the price, the volume, the quality and the duration of the contract."