Dr. Anthony Fauci quietly worked behind the scenes to help cast doubt on the Wuhan lab leak possibility in favor of the natural origins hypothesis during the early months of the COVID-19 pandemic, newly released emails show.

Fauci, the head of the National Institutes of Health’s National Institute of Allergy and Infectious Diseases, appeared to provide guidance to scientists who pushed back against the lab leak hypothesis, and he shared articles with reporters and other health officials that critiqued the possibility that COVID-19 may have escaped from a Chinese government lab. The communications by President Joe Biden‘s chief medical adviser, who has led NIAID since 1984, were part of more than 3,200 pages of emails obtained by BuzzFeed through the Freedom of Information Act.