World Health Organization (WHO) investigators visited the Wuhan Institute of Virology on Wednesday, as the team of experts continue to seek answers in their pursuit of the origins of the coronavirus pandemic.

COVID-19 was first identified in China's central city of Wuhan in December 2019 and the WHO team, led by virus expert Peter Ben Embarek, arrived at the heavily guarded laboratory at around 9:30 a.m (0130 GMT) local time.

"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," WHO team member Peter Daszak, who is the president of NGO the EcoHealth Alliance, said as he arrived at the facility.

Tight security

Reporters followed the WHO investigators to the facility, but as with past visits, there was no direct access to the team of experts.

Security guards paid close attention to onlookers, and journalists in particular, amid thick morning fog.

Conspiracy theories

The Wuhan Institute of Virology has been subject of several conspiracy theories that suggest a leak could have caused the city's first outbreak of COVID-19.

Most scientists reject the notion, but some have speculated that a virus captured from the wild could have figured in experiments at the lab, before escaping via an infected member of staff.

WHO will follow the evidence

The WHO investigators, meanwhile, said they would not rule anything out prematurely.

"We're all aware of the hypotheses around the potential involvement of the lab in this and we're certainly going to ask questions about all of the key aspects of the Wuhan Institute of Virology," the WHO's Peter Daszak told Sky News ahead of the visit.

"Everything's on the table and we're keeping an open mind."

Some scientists have asked China to reveal details of all coronavirus samples examined at the lab, to see which most closely resembles SARS-CoV-2, the virus that causes the respiratory disease.

Following 14 days in quarantine, the WHO team, made up of specialists from 10 different countries, has visited hospitals, research institutes and a wet market linked to many of the early coronavirus infections.

jsi/msh (AP, Reuters)