US President Donald Trump gave new life to rumours that have circulated online for months when he said on Thursday he had seen evidence that the coronavirus originated in a laboratory in the Chinese city of Wuhan.
Mr Trump did not mince words when asked if he had viewed evidence that gave him a "high degree of confidence" the virus came from the Wuhan Institute of Virology.
"Yes, yes I have," he said, refusing to give specifics. "I can't tell you that. I'm not allowed to tell you that."
The theory that the virus responsible for the Covid-19 pandemic was the result of human error at a Wuhan laboratory has been dismissed by scientists and medical experts, including at the World Health Organisation. They cite an overwhelming amount of evidence that points to the virus originating in a Wuhan wet market and jumping from animals to humans.
Secretary of State Mike Pompeo indicated he had not seen the definitive evidence Mr Trump referred to.
"We don't know precisely where it began," he said.
"We don't know if it came from the Wuhan Institute of Virology. We don't know if it emanated from the wet market or yet some other place. We don't know those answers."
Mr Trump’s statement comes amid a growing standoff between the US and China as the two countries exchange conspiracy theories that pin blame on each other for the pandemic.
China has vigorously denied the idea that a laboratory in Wuhan was behind the virus, instead peddling the idea that the US military created the virus.
"Even though information surrounding the coronavirus is a matter of science and medicine, the handling of the outbreak has been politicised in many countries," Masato Kajimoto, a researcher on misinformation at the University of Hong Kong told The National.
US intelligence analysts have been pressured by Trump administration officials to find evidence that could link the virus' origin to a Wuhan laboratory, a New York Times report found.
The US intelligence community said on Thursday that it had investigated the matter and concluded that the coronavirus originated in China but was not man-made or engineered.
"All available evidence to date suggests that the virus has a natural animal origin and is not a manipulated or constructed virus," the WHO said in April.
“Evidence does not support that SARS-CoV-2 is a laboratory construct. A constructed virus would show a mix of known elements within genomic sequences.”
Despite experts consistently denouncing its validity, speculation continues to swirl about a top-secret lab in the ground-zero of the pandemic.
“Rumours about Covid-19 stand out because they don't stay within certain communities and/or in particular languages. This is a truly universal issue and almost everyone around the globe is concerned,” said Dr Kajimoto.
“Naturally, when there are more people who are eager to get and share information, unsubstantiated rumours and bogus claims get distributed faster and wider.”
Addressing the rampant rumours, US General Mark Milley, the chairman of the Joint Chiefs of Staff, backed scientists in April when he said “the weight of evidence seems to indicate natural [origin].”
When further pressed about whether Covid-19 originated in a laboratory, Gen Paul Friedrichs, a top US military surgeon, said, "If I could just be clear, there is nothing to that.”
Academic papers share unproven claims
The unauthenticated claim first gained weight when Botao Xiao, a professor at the South China University of Technology, uploaded a paper to ResearchGate that alleged "the killer coronavirus probably originated from a laboratory in Wuhan."
The academic paper did not undergo a peer-review process, a necessary step to validate a researcher’s findings.
The evidence used in the paper to link Covid-19 to two Wuhan labs was thin, with the researchers primarily relying on the labs' geographic proximity to Wuhan’s wet market and the fact that they worked with bats.
Mr Xiao told The Wall Street Journal he had removed his paper from the website because his findings were "not supported by direct proofs".
Other conspiracy theories were fuelled by a widely read scientific paper from the Indian Institute of Technology, since withdrawn, claiming that proteins in the coronavirus shared an "uncanny similarity" with those of HIV.
In response to the unproven articles spreading in academic publications during a public health crisis, a group of 27 scientists from nine countries issued a statement in The Lancet denouncing the rumours.
“The rapid, open, and transparent sharing of data on this outbreak is now being threatened by rumours and misinformation around its origins. We stand together to strongly condemn conspiracy theories suggesting that Covid-19 does not have a natural origin.”
But by the time these unproven papers were removed and denounced by experts, the damage had been done as the claims were already embedded in online rumour mills.
"There is zero evidence that it was made in a lab, only accusations. Accusations do not work in the world of science," Dr Vincent Racaniello, a professor of microbiology and immunology at Columbia University told The National.