Chinese authorities refused the 10-member investigation team entry into the country at the last minute. China has said the team’s visas were not yet approved, as two of the scientists had already made their way to the country.
Tedros Adhanom Ghebreyesus, Chief of the WHO, expressed his concern over China’s blockade of the investigation team.
He said in a press conference: “I’m very disappointed with this news, given that two members have already begun their journeys, and others were not able to travel at the last minute.
“But I have been in contact with senior Chinese officials. And I have once again made it clear that the mission is a priority for WHO and the international team.
“We’re eager to get the mission underway as soon as possible.”
Dr Mike Ryan, assistant director general of emergencies at the WHO, added the delay was centred around visa clearances.
Dr Tedros has “impressed on Chinese officials” how critical the investigation is, according Dr Ryan.
He added: “This is frustrating and as the director general said this is disappointing.
“This disappointment has been expressed very clearly.”
Both Dr Ryan and Dr Tedros hoped it was “just a logistical and bureaucratic issue that can be resolved very quickly” in the “coming hours”, but one member has returned to their home country.
The investigation will attempt to identify how COVID-19 moved from animals to humans.
Earlier investigations into the virus traced it to a wet market in Wuhan, in the Hubei province in China.
Chinese scientists have categorically rejected accusations it was completely responsible for the virus.
Chinese state media has also attempted to shift the blame for the pandemic onto other countries, claiming the virus originated in Australia and other nations.
The Government’s People’s Daily newspaper claimed on Facebook in November that “all available evidence suggests that the coronavirus did not start in central China’s Wuhan”.
Quoting Zeng Guang, former chief epidemiologist at the Chinese Centre for Disease Control and Prevention, the outlet added: “Wuhan was where the coronavirus was first detected but it was not where it originated.”
But no available evidence indicates the virus originated in other countries.
Garrett Grigsby, from the US Department of Health and Human Service, has lashed out at the WHO for the investigation mission.
He said the planned hunt for the origins were “inconsistent” with the WHO’s mandate, and added: “Understanding the origins of COVID-19 through a transparent and inclusive investigation is what must be done to meet the mandate.”
President Donald Trump has also criticised the investigation, after completely blaming the Chinese government for the pandemic over the last year.