US President Joe Biden has ordered intelligence agencies to investigate the emergence of Covid-19, amid growing controversy about the virus’s origins.
In a statement, Mr Biden asked US intelligence groups to “redouble their efforts” and report to him within 90 days.
Covid-19 was first detected in the Chinese city of Wuhan in late 2019.
More than 168 million cases have since been confirmed worldwide and at least 3.5 million deaths reported.
Authorities linked early Covid cases to a seafood market in Wuhan, and scientists believed the virus first passed to humans from animals.
But recent US media reports suggest growing evidence the virus could instead have emerged from a laboratory in China.
Beijing has condemned the reports and suggested it could have come from a US laboratory instead.
In what passes for relative transparency in the US government, the Biden administration has conceded the American intelligence community is split on Covid-19’s origins – it could be the lab or animal-to-human contact – and no-one is near certain about it.
That marks a big shift from the derision heaped on the lab theory by many in the media and politics last year, when Donald Trump, Secretary of State Mike Pompeo, Senator Tom Cotton and others floated the idea.
Mr Trump and Mr Pompeo didn’t help the situation, however, as they were coy about the grounds for their suspicion. And their theories floating alongside more far-fetched ones, such as that the disease was manufactured in a Chinese lab. That possibility still seem highly unlikely.
The public may never know the full truth about the virus’ origins, particularly if China continues to be uncooperative. Mr Biden is pledging a full investigation, however, and if the US finds conclusive evidence of a lab leak, it will mean more than just a few prominent figures having to eat crow and re-evaluate their trust in authoritative “conclusions”. It could place very real strain on US-China relations for years to come.