Two Fox News programs promoted a debunked theory about the origins of the coronavirus disease in Wuhan, China, echoing former White House adviser Steve Bannon and his billionaire benefactor Guo Wengui. The discredited speculation, which The Washington Post labeled a “fringe theory” and PolitiFact identified as “false,” posits that the coronavirus epidemic was engineered in a high-security laboratory housed in the Wuhan Institute of Virology. Rutgers University professor of chemical biology Richard Ebright told the Post that “based on the virus genome and properties there is no indication whatsoever that it was an engineered virus.”

Despite lack of evidence, Fox anchor Martha MacCallum and Fox host Tucker Carlson lent credence to this theory on their respective February 18 broadcasts. MacCallum, who Fox News touts as a “straight news” anchor, hosted Sen. Tom Cotton (R-AR) for a clean-up interview after he appeared with Maria Bartiromo on Fox News over the weekend pushing the evidence-free narrative, which was then written up and debunked in The New York Times. (Cotton had also pushed the theory during a Senate Armed Services Committee hearing on January 30.) MacCallum pushed back once lightly, citing Ebright’s assertion about the virus genome as well as criticism from CNN’s Chris Cillizza.

During the 8 p.m. hour, Tucker Carlson, who has floated the theory before, continued the network’s unfounded fearmongering about the origins of the coronavirus. In an interview with The Washington Times’ Bill Gertz, whose thinly sourced reporting Bannon has used as a launch pad for his reckless speculation, Carlson cited “a few actual experts” who are “considering” the theory. (However, it is unclear who those experts are or if they exist.) He also claimed it was “worth getting to the bottom of” speculations about the coronavirus' origins because his audience had “probably seen that on the internet.”

Gertz has appeared multiple times on Steve Bannon’s War Room: Pandemic podcast. Bannon’s regular guest Dr. Steven Hatfill, an expert who previously worked at the U.S. Army Medical Research Institute of Infectious Diseases, has repeatedly refuted the theory on the show. But this has not stopped the former Trump adviser from repeating the baseless claim, as it continues to metastasize throughout the right-wing media.