The coronavirus pandemic definitely started in China, according to a scientific study that has traced the 'mother' of all Covid-19 infections and its initial descendants to the country.
The groundbreaking research by US experts, which analysed samples from thousands of coronavirus patients, also established that the outbreak almost certainly began in October 2019.
Their findings challenge Beijing's attempts to divert attention to other nations as the pandemic's birthplace, with officials arguing that the virus may have been imported into Wuhan, in China's Hubei province.
The study's suggested date of first infections fits with claims from the US State Department that 'several' researchers at the top-security Wuhan Institute of Virology fell sick in the autumn of 2019.
The explosive findings come as a World Health Organisation team belatedly begins its inquiry in China into the origins of the pandemic amid fears that its work will be stifled by the Chinese dictatorship.
China has promoted dubious theories that the virus emerged outside its borders. Even last week, a foreign ministry spokeswoman claimed it might have come from a US military base and laboratory in Maryland.
Shi Zhengli, a Wuhan scientist whose cutting-edge research has aroused suspicions, has also just published a paper arguing the disease 'existed for some time before the first cases were described in Wuhan'.
China's stance has provoked dismay around the world. 'The evidence of the virus emerging from Wuhan is compelling but Beijing continues to blame others,' said Tom Tugendhat, the Tory MP and chairman of the Foreign Affairs Select Committee.
The new US study is by a team of molecular epidemiology detectives at the Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia. They used modelling techniques developed in tracking cancer mutations to trace the evolution of Sars-Cov-2 – the coronavirus strain that causes Covid-19 – back to the 'progenitor', or ancestor, genome behind the 101 million infections worldwide.