Shi Zhengli works at a laboratory at the Wuhan Institute of Virology.

Shi Zhengli, a leading coronavirus scientist from the Wuhan Institute of Virology, dismissed conspiracy theories that her institute had leaked the COVID-19 virus, in an interview with the journal Science.

Conspiracy theories about the origin of the virus arose soon after the epidemic began. Though the global scientific consensus is that it could not have been lab-engineered, some pundits and politicians have blamed the institute as the source of the outbreak without citing evidence.

"US President (Donald) Trump's claim that SARS-CoV-2 was leaked from our institute totally contradicts the facts," she told Science in the written interview. "It jeopardizes and affects our academic work and personal life. He owes us an apology."

Shi said that her lab first encountered SARS-CoV-2, the virus responsible for COVID-19, on Dec 30 when examining samples from patients with pneumonia of unknown origin. She said she believed the virus may have originated in bats and jumped to humans via an intermediate host, though she said the mechanism for that is still unknown.

Nevertheless, she said, "we have done bat virus surveillance in Hubei province for many years but have not found that bats in Wuhan or even the wider Hubei province carry any coronaviruses that are closely related to SARS-CoV-2".

There is also speculation that the novel coronavirus originated in a bat cave near the mining town of Tongguan in Yunnan province's Mojiang county. But, Shi said, "To date, none of the nearby residents is infected with coronaviruses. Thus the claim that the so-called patient zero was living near the mining area and then went to Wuhan is false."

At Wuhan's Huanan seafood market, where the outbreak was first reported, Shi said small traces of the virus' genetic material had been detected in environmental samples from sources such as door handles, the ground and sewage in the market.

But scientists did not detect the virus in frozen animal samples from the market, or from farmed animals and livestock from areas around Wuhan and Hubei province, she said. "The Huanan seafood market may just be a crowded location where a cluster of early novel coronavirus patients was found."

No staff members or students at the Wuhan institute have been infected by the novel coronavirus, Shi stressed in response to rumors that the "patient zero" of COVID-19 was a researcher from the institute.

Daniel Lucey, an infectious disease expert at Georgetown University, told Science that Shi's response is "a big contribution" and "there are a lot of new facts that I wasn't aware of. It's very exciting to hear this directly from her."

Kristian Andersen, an evolutionary biologist at Scripps Research, a nonprofit medical research facility in the United States, said Shi's answers are "logical, genuine and stick to the science, as one would have expected from a world-class scientist and one of the leading experts on coronaviruses".

Edward Holmes, an evolutionary biologist at the University of Sydney, said the answers are "a clear, comprehensive and believable account "of what occurred at the Wuhan institute.