The home of Andriy Yermak was searched Friday by investigators probing an alleged $100 million kickback scheme.

A top Ukrainian official at the heart of peace talks resigned on Friday after being thrust into the center of a massive corruption scandal, threatening to further weaken President Volodymyr Zelenskyy at a crucial moment in negotiations to end Russia’s war.

Andriy Yermak’s, Zelenskyy’s powerful chief of staff, decision to quit came hours after his home was searched early Friday by investigators with Ukraine’s National Anticorruption Bureau, the NABU, which is leading the $100 million kickback probe involving the country’s energy sector.

Zelenskyy said in a later video statement that Yermak had handed in his resignation and he was looking for his replacement. “Russia really wants Ukraine to make mistakes,” he said. “There will be no mistakes on our part.”