N.I.H. Leader Rebuts Covid Lab Leak Theory at House Hearing

The suspicions revolve around $8 million in grants to EcoHealth Alliance, a nonprofit that was collaborating on coronavirus research with scientists at the Wuhan Institute of Virology, in the city where the pandemic began.

Late last month, an internal federal watchdog agency found that the N.I.H. had made significant errors in its oversight of those grants. In a 64-page report, the Office of Inspector General at the federal Department of Health and Human Services outlined missed deadlines, confusing protocols and misspent funds — raising and reinforcing concerns about the government’s system for monitoring research on potentially risky pathogens.

The Wuhan studies looked at how animal coronaviruses, especially bat coronaviruses, evolve naturally in the environment and have the potential to become transmissible to the human population. N.I.H. officials have long maintained that the viruses studied in Wuhan “could not have possibly been the source of SARS-CoV-2 or the Covid-19 pandemic,” as an agency website puts it — the sentiment Dr. Tabak reiterated on Wednesday.

But Representative Morgan Griffith, Republican of Virginia, who leads one of the two subcommittees that convened Wednesday’s hearing, was not persuaded by Dr. Tabak.

While he conceded that he did not have absolute proof that a lab leak caused the pandemic, Mr. Griffith said that, as a lawyer, he did not feel the need to eliminate “all doubts.” Rather, he said, he is convinced beyond “a reasonable doubt,” in part because China has withheld information from the United States and in part because of the irregularities uncovered by the inspector general.

“What he has is a lack of evidence,” Mr. Griffith said of Dr. Tabak. “He does not have evidence that they didn’t study the coronavirus that became Covid-19.”

Representative Diana DeGette, Democrat of Colorado and a longtime member of the committee, has come to the opposite conclusion with the same set of facts. After reviewing reports and attending a classified briefing, she said, she agrees with scientists who say the pandemic was most likely caused by “viral spillover” — the virus jumping from animals to humans — at a wet market in Wuhan.