BEIJING (BLOOMBERG) - China accused the US of promoting theories that the coronavirus escaped from a high-security lab in Wuhan, as a fresh report about sick workers at the facility prompted Beijing to reaffirm denials.

"The report that you mentioned about three people getting sick, that is not true," Foreign Ministry spokesman Zhao Lijian told a regular briefing on Monday (May 24) in Beijing.

Mr Zhao was responding to a Wall Street Journal report that a trio of researchers from the Wuhan Institute of Virology - a lab in the city where the first Covid-19 outbreak was identified - had fallen ill and sought hospital care in November 2019.

The facility has previously denied claims of workers getting sick, including a US State Department fact sheet publish in January that asserts that several researchers from the institute became sick in autumn 2019.

Mr Zhao said the US has been hyping the lab-leak theory.

China has sought to frame the claims as conspiracy theories created to divert attention from the US government's own handling of the coronavirus, and suggested that the Fort Detrick military base in Maryland should be investigated.

"There is suspicion about the activities at Fort Detrick and the more than 200 biolabs run by the US," Mr Zhao said at the briefing.

"The US has been hyping up the theory of a lab leak but does it really care about the study of origin tracing or is it trying to divert attention? We hope the relevant US departments can make a clarification and give the world a clear answer."

While the World Health Organisation-led investigation in China earlier this year found it was "extremely unlikely" the coronavirus came from a laboratory leak, scientists have sought more data.

WHO director-general Tedros Adhanom Ghebreyesus said following the probe that it did not adequately analyse the possibility of a lab accident, adding that he is ready to deploy additional resources.