India, July 29 -- Former National Institute of Allergy and Infectious Diseases (NIAID) Director Anthony Fauci returned to Capitol Hill on Wednesday for a closely watched Senate hearing led by Republican Senator Rand Paul, reigniting a years-long dispute over the origins of COVID-19 and government-funded virus research.

However, rather than answering lawmakers' questions, Fauci invoked his Fifth Amendment right against self-incrimination, accusing Paul of running an "unhinged" campaign to see him prosecuted.

The hearing before the Senate Homeland Security and Governmental Affairs Committee came after Fauci was subpoenaed to testify by Paul, who has repeatedly accused him of misleading Congress about COVID-19-related research.

Here's wha...