World Health Organisation investigators have visited a research centre in the Chinese city of Wuhan that has been the subject of speculation about the origins of coronavirus.

The WHO team’s visit to the Wuhan Institute of Virology on Wednesday is a highlight of its mission to gather data and search for clues as to where the virus originated and how it spread.

One of China’s top virus research labs, the institute built an archive of genetic information about bat coronaviruses after the 2003 outbreak of Severe Acute Respiratory Syndrome.

That has led to unproven allegations it may have a link to the original outbreak of COVID-19 in Wuhan in late 2019.

China has strongly denied that possibility and promoted theories the virus may have originated elsewhere or even been brought into the country from overseas with imports of frozen seafood tainted with the virus.

That notion has been roundly rejected by international scientists and agencies.

The institute’s deputy director is Shi Zhengli, a virologist who worked with Peter Daszak, a zoologist on the WHO team mission, to track down the origins of SARS that originated in China and led to the 2003 outbreak.

She has published widely in academic journals and worked to debunk theories espoused by the Trump administration and other American officials that the virus is a bioweapon or a “lab leak” from the institute.

Following two weeks in quarantine, the WHO team – which includes experts from 10 nations – has visited hospitals, research institutes and a traditional wet market linked to many of the first cases.

The visit followed months of negotiations as China seeks to retain tight control over information about the outbreak and investigation into its origins, possibly to avoid blame for alleged missteps in its early response.

Confirmation of the origins of the virus is likely to take years.

Pinning down an outbreak’s animal reservoir typically requires exhaustive research including taking animal samples, genetic analysis and epidemiological studies.

One possibility is that a wildlife poacher might have passed the virus to traders who carried it to Wuhan.

-AAP