Family members say they face immense pressure from Chinese authorities who have interrogated and threatened them.
A World Health Organization-led team of experts investigating the origins of COVID-19 have visited Huanan market, the now-shuttered wholesale seafood market in the Chinese city of Wuhan where the novel coronavirus was initially detected.
The team arrived at Huanan on Sunday amid heavy security, with additional barricades set up outside a high blue fence surrounding the market, and left in a convoy after about one hour.
“Very important site visits today – a wholesale market first & Huanan Seafood Market just now,” Peter Daszak, a zoologist with the US group EcoHealth Alliance and a member of the WHO team, said in a tweet.
“Very informative & critical for our joint teams to understand the epidemiology of COVID as it started to spread at the end of 2019.”
The experts did not take questions from journalists. One flashed a thumbs-up sign when reporters asked how the trip was going.
Since being released from a two-week quarantine on Thursday, the team has visited hospitals and markets, as well as an exhibition commemorating Wuhan’s COVID battle, which included a 76-day lockdown of the city of 11 million.
A single visit by scientists is unlikely to confirm the virus’s origins. Pinning down an outbreak’s animal reservoir is typically an exhaustive endeavour that takes years of 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.
The WHO, which has sought to manage expectations for the mission, said on Friday that team members would be limited to visits organised by their Chinese hosts and would not have any contact with community members because of health restrictions.
No full itinerary for the team’s two weeks of fieldwork was announced, and journalists covering the tightly controlled visit have been kept at a distance from team members.
Public access to the sprawling Huanan Seafood Wholesale Market has been restricted since it was shut at the beginning of last year.
Before its closure, the market bustled with hundreds of stalls divided into sections for meat, seafood and vegetables.
Now it stands as a landmark in a city that was traumatised as the original epicentre of what became a global pandemic.
On December 31, 2019, after four cases of a mystery pneumonia were linked to the market, it was shuttered overnight. By the end of January, Wuhan had gone into a 76-day lockdown.
Experts say the Huanan market still plays a role in tracing the origins of the virus, since the first cluster of cases was identified there.
On the anniversary of the Wuhan lockdown, Al Jazeera’s Investigative Unit released 3 Days that Stopped the World, which showed the days leading up to the lockdown of the city. The footage, smuggled out of China because it was censored by the Chinese government, showed how the city hospitals struggled to treat patients while officials tried to keep journalists from reporting on the increasing number of infected.
The WHO-led probe in Wuhan has been plagued by delays, concern over access, and bickering between China and the United States, which accused China of hiding the extent of the initial outbreak and criticised the terms of the visit, under which Chinese experts conducted the first phase of research.
The origins of the virus have become highly politicised and some Chinese diplomats and state media have thrown support behind theories the virus potentially originated in another country.
The team had been set to arrive in Wuhan earlier in January, and China’s delay of the visit drew rare public criticism from the head of the WHO, which then-US President Donald Trump accused of being “China-centric”.