A team from the World Health Organization on Wednesday visited a research laboratory in the central Chinese city of Wuhan, from which the pandemic-causing novel coronavirus is rumored to have accidentally escaped, in a bid to trace the origins of it.
The administration of former U.S. President Donald Trump advanced a theory that the Wuhan Institute of Virology might be the birth of the virus, claiming some researchers there developed symptoms consistent with COVID-19 in the fall of 2019.
China has rejected the allegation, further fueling tensions between the world's two major powers that have been at odds over several issues including business practices, trade, state-of-the-art technology, Hong Kong, Taiwan and the South China Sea.
All eyes are on whether the investigation by the WHO group will help identify the sources of the virus, with more than a year having passed since the first infection was spotted in Wuhan, a business and transportation hub with a population of around 11 million people.
The laboratory -- known for having studied a coronavirus triggering the severe acute respiratory syndrome, or SARS -- is expected to provide data to the WHO team, comprising 10 experts.
Although the probe was closed to the public, one of the experts told Kyodo News that the group was scheduled to observe two main research rooms at the laboratory and talk with Shi Zhengli, a virologist famous for her work on coronavirus in bats.
On Sunday, the WHO team carried out a one-hour investigation into a Wuhan market, at which many people were confirmed to have contracted the new virus in the early days of the outbreak in late 2019.
The market, where wild animals such as bats and snakes had been sold alongside seafood, has been closed since January 2020. It has been sanitized thoroughly by Chinese authorities.
On Tuesday, the WHO experts visited a provincial animal health facility in the city wearing protective suits, as animals are suspected of having initially transmitted the virus to humans.
The WHO has been trying to clarify the process of how bats, believed to be the main natural host of the virus, passed it to other animals, sources close to the matter said.
After quarantining for two weeks, the WHO experts began a full-fledged probe in late January. They are likely to complete the investigation in Wuhan by the Feb. 11 start of the weeklong Lunar New Year holidays, the sources added.
The experts had originally planned to visit China early last month, but their arrival was delayed after it took longer than expected for Beijing to finalize granting permission for the group to enter the country.
WHO Director General Tedros Ghebreyesus had said that he was "very disappointed" with China.
The WHO sent a small team to China for a preliminary probe in July, but they did not visit the market or the laboratory.
Since first being detected in Wuhan, the virus erupted into a pandemic that has infected over 103 million people and caused more than 2.2 million deaths across the globe, according to data compiled by Johns Hopkins University.
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