Former US health official Anthony Fauci invoked his Fifth Amendment right at a Senate hearing on Wednesday, refusing to answer questions about the origins of Covid-19 for fear his testimony could be used to pursue a perjury case against him. The refusal enraged Republican senators, with Josh Hawley accusing Fauci of showing "contempt" for Congress, while Democrats including Maggie Hassan came to his defence; the session grew heated when one of Fauci's own lawyers was ejected after repeatedly interjecting.

The hearing was called by Senator Rand Paul, a long-time proponent of the Wuhan lab-leak theory, who days earlier released over 1,000 pages of Fauci's pandemic-era writings and opened the session by claiming they showed Fauci privately favoured the lab-leak explanation while publicly insisting the virus emerged naturally. Fauci's diary entries actually show him weighing both theories early in the pandemic before concluding a natural origin was more likely, while still keeping "an open mind" about a lab leak; the World Health Organization said in 2025 that natural origin remains the "best supported" theory, though the question is officially "inconclusive". Fauci accused Paul of an "obvious obsession" with seeing him jailed and said he had already testified under oath at previous hearings.