But it is a complete falsehood. Why? The genome of the virus has been decoded and published. Scientists who have looked at the results have no doubt it is a naturally evolving virus. But while it may be false, the theory is not fringe any more because Cotton is actively promoting it.

This has prompted a rebuttal from Chinese ambassador to the US Cui Tiankai.

“This will create panic,” he said. “It will fan up racial discrimination, xenophobia, all these things that will really harm our joint efforts to combat the virus.”

The senator has been on a tear since January, calling for all Americans to leave China, a ban to prevent Chinese nationals from entering the US and a “Manhattan Project-level effort to create a vaccine”, a reference to the secret project that produced the world’s first atomic bombs.

China’s ambassador condemns ‘rumours’ about coronavirus origin by US senator

But to date, there has not been a single death related to the new virus in the US.

Cotton has hit back on Twitter: “Here’s what’s not a conspiracy, not a theory: Fact: China lied about virus starting in Wuhan food market.”

That was the initial suspicion, but it is now being questioned, partly due to an updated analysis, published in The Lancet on January 24, by a team of Chinese researchers from state-run institutions.

Cotton goes on: “Fact: super-lab is just a few miles from that market[.] Where did it start? We don’t know. But burden of proof is on you & fellow communists. Open up now to competent international scientists.”

Leaving aside his absurd logic, the Wuhan institute is actually open to qualified outsiders, Americans no less.

The lab has close institutional ties with the Galveston National Laboratory at the University of Texas Medical Branch and was partly built by French engineers.

Senator Cotton, stop making a fool of yourself.