China has tried to blame Spain for the new strain of coronavirus while suggesting the deadly disease originated in Europe and not Wuhan.
The first cases were detected in the Chinese city of Wuhan in late 2019 - with many involving workers at a wet market - before the virus rapidly spread around the world, killing more than 525,000 people.
China has been accused of covering up its initial outbreak by silencing doctors who tried to warn the public, muzzling scientists researchers who identified it as a new coronavirus, and failing to alert the rest of the world until it was too late.
The World Heath Organisation (WHO) is set to begin a "scoping mission" to China next week as part of its efforts to trace the origin of Covid-19 as the pandemic rages on in countries such as the US, Brazil, Mexico and Russia.
There are concerns their work could be impeded.
International experts suspect the virus originated in bats.
In China's latest attempt to deflect blame, Wang Guangfa, a senior health adviser with the government, told state media that WHO officials should look at a number of countries, including Spain, as part of their investigation.
He cited research in Barcelona which is said to have detected Covid-19 in wastewater sample from March 2019, about nine months before doctors in Wuhan became alarmed by the first cluster of cases.
But independent experts have cast doubts on the research, suggesting it was flawed and saying there is strong evidence the virus first emerged in China in late 2019.
Professor Francois Balloux, director of the UCL Genetics Institute in London, told the Telegraph: “The most plausible explanation is sample mix-up/contamination."
The WHO team that will travel to China will include an animal health expert and an epidemiologist.
Their work will focus on the origin of the virus and it will be vital to understanding outbreaks and preventing future ones.
Dr Peter Daszak, president of EcoHealth Alliance, told the Telegraph: “Doing the science of this is hard, it's expensive, it takes a long time.
"But it's worth doing because then you can actually make intelligent decisions that will save lives in the future... and prevent another pandemic.”
Dr Daszak said there are concerns that tracing Covid-19 will become tougher as the issue is politicised.
He suspects the virus was spreading for some time before reaching Wuhan, a city of 11 million people, through a wildlife trade that connects rural areas with bat caves to large cities.
Since the first cluster of cases emerged in Wuhan in December, more than 11 million confirmed infections have been reported around the world, but the total is believed to be far higher.
More than 525,000 deaths linked to Covid-19 have been confirmed.
Spain, meanwhile, enforced a new lockdown on more than 200,000 people in the north-eastern region of Segria on Saturday after several new outbreaks of the coronavirus were detected.
Residents are not allowed to leave the region and no-one is allowed to enter.
However, they will not be confined to their homes as was the case in Spain's original strict lockdown in March.