Dr Anthony Fauci evaded more than 100 questions about Covid, the lab leak theory and his ties to Wuhan during a landmark Congressional hearing Monday.
House Republicans who quizzed the ex-White House advisor said he 'played semantics' to avoid conceding that he funded dangerous research in China that is feared to have started the pandemic.
Dr Fauci, 82, also admitted that he signed off on millions of dollars worth of grants without reviewing the proposals - and appeared to admit his agency had little oversight of the foreign labs it bankrolled.
The all-day probe on Monday will be followed by another seven hours of questioning behind closed doors today.