In his first public testimony since stepping down from government office at the end of 2022, Dr. Anthony Fauci on Monday fended off a variety of attacks from Republican politicians at a fiery hearing called to discuss lessons learned during the pandemic.

Fauci, appearing voluntarily before the House Select Subcommittee on the Coronavirus Pandemic, denied a wide range of claims that have been made against him in recent years.

Various Republican subcommittee members asked Fauci about funding for virology research in China that came from the National Institutes of Health and that they said he had approved. Some conspiracy theories suggest that such research led to the coronavirus being leaked from a lab. Fauci also answered questions about whether his staff endeavored to conceal the nature of that research from the public.

In his opening statement, Fauci said it’s possible the virus had leaked from a lab — he said that, given that the pandemic’s origins remain unknown, he personally keeps an open mind. But he denied concealing any relevant information about a potential leak.

“I don’t think the concept of there being a lab leak is inherently a conspiracy theory,” Fauci said. “What is conspiracy is the kind of distortions of that particular subject, like it was a lab leak and I was parachuted into the CIA like Jason Bourne and told the CIA that they should really not be talking about a lab leak. That’s the conspiracy.”

The subcommittee did not present any evidence linking Fauci to the coronavirus’ origins.

Fauci has emerged as one of the people most vilified by supporters of former President Donald Trump, with many blaming him for the pandemic based on a wide array of false or misleading claims. Calls to prosecute Fauci for unspecified crimes have become common on the right.

In his testimony Monday, Fauci explained that he participated in a call in early 2020 with about a dozen scientists in which they discussed the virus’ emergence and the possibility that it may have originated in a lab. Fauci said that, after further investigation, the members of that group concluded that the virus most likely spilled over from animals to humans.

“The accusation being circulated that I influenced the scientists to change their minds by bribing them with millions of dollars in grant money is absolutely false and simply preposterous,” he said.

Fauci testified about the same subjects before the same subcommittee in a closed-door hearing in January.

Before retiring, Fauci also testified before Congress many times about his leadership during the pandemic. He directed the National Institute of Allergy and Infectious Diseases from 1984 to 2022 and was part of then-President Donald Trump’s coronavirus task force, as well as President Joe Biden’s Covid response team.

During the hearing Monday, Democrats championed Fauci as a stalwart public servant and accused Republicans of unnecessarily vilifying him.

“Some of our colleagues in the United States House of Representatives seem to want to drag your name through the mud. They’re treating you, Dr. Fauci, like a convicted felon,” said Rep. Jamie Raskin, of Maryland.

But in a combative moment that prompted consternation from several of her House colleagues, Republican Rep. Marjorie Taylor Greene, of Georgia, said Fauci belonged in prison and did not deserve to have a medical license. She added that Fauci’s medical guidance led children to be “muzzled” with masks in schools, and — in a strange tangent — accused him of signing off on experiments involving the torture of beagles.

As she left the hearing, Greene doubled down in comments to NBC News.

“Fauci belongs in prison. He should be tried for mass murder, and he should be tried for crimes against humanity. That’s how I feel after that hearing,” she said.

Multiple Democrats apologized to Fauci for the insult.

“This might be the most insane hearing I’ve actually attended,” said Rep. Robert Garcia, of California. “I’ve only been on Congress for a year and a half, but I am so sorry that you are subjected to those level of attacks and insanity.”

The Republican-led House Select Subcommittee on the Coronavirus Pandemic has been investigating the coronavirus’ origins for months, with a primary focus on the possibility of a lab leak, as well as on mask and vaccine mandates.

Much of Monday’s hearing focused on EcoHealth Alliance, a nonprofit research group that received U.S. government funding for pandemic prevention work. In May, the Department of Health and Human Services suspended funding to the organization after concluding that it had failed to adequately monitor research it was involved in at the Wuhan Institute of Virology in China and did not turn over requested materials or submit progress reports on time. 

Rep. Brad Wenstrup, an Ohio Republican who is chairman of the House subcommittee, said Monday that Fauci’s leadership allowed the president of EcoHealth Alliance, Peter Daszak, to use millions in taxpayer dollars to conduct risky experiments in Wuhan that involved modifying a coronavirus.

Members of the subcommittee have alleged that EcoHealth Alliance facilitated so-called gain-of-function research, which involves enhancing a virus to make it more transmissible. But EcoHealth Alliance has said its work did not meet the definition of such research.

Republicans also questioned Fauci’s relationship with one of his former aides, David Morens, who used personal email accounts to correspond with Daszak, a friend of his. The subcommittee members said that some of Morens’ emails offer evidence that he tried to skirt public records laws.

Fauci said that Morens had violated NIAID policy and that “from what we know now,” it appears Morens’ communication with Daszak amounted to a conflict of interest.

But Fauci added that he never conducted official business using his own personal email.

He also emphasized that no viruses studied with funding from the National Institutes of Health could have evolved into SARS-CoV-2.

Fauci has been a central focus of extreme conspiracy theories that have circulated online since early in the pandemic, said Cameron Hickey, CEO of the National Conference on Citizenship, a nonprofit focused on strengthening U.S. democracy.

“Anti-vaccine activists see Anthony Fauci as a ringleader in the effort to spread lies about the origins of the pandemic, as a profiteer who is making money off the vaccine and as a power-hungry part of the ‘swamp’ that perpetuated unnecessary public health precautions like masking, isolation and social distancing,” Hickey said in an email.

Fauci said Monday that he and his family continue to be harassed.

“There have been credible death threats, leading to the arrests of two individuals — and credible death threats mean someone who clearly was on their way to kill me. And it’s required my having protective services essentially all the time. It is very troublesome to me. It is much more troublesome because they’ve involved my wife and my three daughters,” Fauci said, his voice choked.