A team of investigators working on behalf of the World Health Organisation (WHO) visited a major virus research laboratory in China's central city of Wuhan, seeking clues to the origins of the Covid-19 pandemic.

Driving through thick morning mist, the team, led by WHO virus expert Peter Ben Embarek, arrived at the heavily guarded Wuhan Institute of Virology at about 9:30am, Reuters reported.

“I am looking forward to a very productive day, meeting the key people here and asking all the important questions that need to be asked,” team member Peter Daszak, who is the president of the EcoHealth Alliance, said from his car as it drove in.

The institute has been at the centre of a number of conspiracy theories that claim a laboratory leak caused the city's first coronavirus outbreak at the end of 2019.