The outgoing Chief Executive Officer of Eskom has told South African police that he recently survived an attempted assassination.
The alleged incident took place a day before de Ruyter resigned.
According to EE Business Intelligence, a person it didn't identify became violently ill after drinking a cup of coffee that was said to have been spiked with cyanide.
He confirmed to the news service that he had filed a complaint with the police, but wouldn't say anything else.
South Africa's economy is being wrecked by a company.
While a search is conducted to find a suitable replacement for De Ruyter, he will remain in his role until March 31.
Almost all of the nation's electricity is supplied by the state power utility. Over the course of a decade, there have been frequent power cuts in South Africa.