Federal Reserve Chairman Kevin Warsh was subjected to intense questioning by Sen. Elizabeth Warren (D-Mass.) regarding potential ethics violations.

On Wednesday, his second day of monetary policy testimony on Capitol Hill, Warsh was grilled by Warren about a $100 million amount he was required to divest after becoming Fed chair, and which he refused to disclose, asking if anyone gave him that amount before he was sworn in.

"Who gave you $100 million right before you were sworn in? Was it a billionaire who has business with the Fed?” asked Warren.

She further pressed if billionaire investor Stanley Druckenmiller, or another billionaire who profits from Federal Reserve decisions, provided him with the money.

Notably, Warsh has longstanding ties to Druckenmiller, having joined Duquesne Family Office after leaving the Fed in 2011 and previously investing tens of millions of dollars in the Juggernaut Fund, which was linked to Druckenmiller’s firm. Those investments have since been divested.