South African power utility Eskom on Sunday said police were investigating whether an attempt was made to poison its outgoing Chief Executive Officer Andre de Ruyter.

Faced with political pressure, De Ruyter resigned on Dec. 14 after failing to solve a crisis in the company that has led to record levels of power cuts in Africa’s most industrialised economy.

After officially taking office in January 2020, De Ruyter led a company-wide clampdown on corruption and organised criminal behaviour, including sabotage of infrastructure, at Eskom plants. His last day in office will be March 31.

“Eskom cannot comment further on the poisoning incident involving the group chief executive, which occurred during December 2022, as the matter is subject to police investigation,” the utility’s head of security said in a statement.

The South African police services did not immediately respond to Reuters’ request for comment. Eskom’s board chairman Mpho Makwana was also unavailable.

The alleged poisoning of De Ruyter was first reported by specialist energy publication EE Business Intelligence on Saturday.