The U.S. government has been politically hyping the coronavirus origin tracing as part of an effort to put forward a conspiracy theory centered at a so-called "laboratory leakage," which has drawn strong opposition from a large number of leading scientists.

There is no evidence to back up the idea that the coronavirus came from a laboratory which only politicizes the issue, said Vincent Racaniello, a Higgins Professor from the Department of Microbiology and Immunology at Columbia University.