A scientist at the forefront of an international effort to track the deadly coronavirus outbreak has shot down claims about the disease’s origins, including that it escaped from a Wuhan laboratory after being genetically engineered.

Trevor Bedford, of the Fred Hutchinson Cancer Research Center in Seattle, rubbished stories circulating on social media that Covid-19 was created at Wuhan Institute of Virology or elsewhere in China, rumours that prompted the World Health Organization to warn of an “infodemic” of false news on the outbreak.

“There is no evidence whatsoever of genetic engineering that we can find,” he said at the American Association for the Advancement of Science meeting in Seattle. “The evidence we have is that the mutations [in the virus] are completely consistent with natural evolution.”