New research claims to have pinpointed the very first Covid cases - 10 years ago.
It is believed that coronavirus may have originated from labourers who worked in a Chinese mine nearly a decade before the pandemic began.
Dr Jonathan Latham claims to have discovered that Covid-19 may have evolved in the body of infected workers.
He says this happened in April 2012 when six mineworkers were admitted to hospital with coronavirus-like symptoms while working in the Mojiang mines, in south-central Yunnan in China.
READ MORE: UK faces an 'uncertain' winter with possible 'multi-strain flu'
Three eventually died after working in a bat-infested cave, the Mirror reports.
According to Dr Latham, the virus that eventually became SARS-CoV-2 and caused Covid-19 may have evolved inside the bodies of these miners before escaping into the population, through samples of the disease that were sent to researchers in Wuhan.
Speaking at a British Medical Journal (BMJ) webinar, Dr Latham said: "The theory requires many hundreds of mutations in one miner to turn into Sars-Cov-2. Decades were crammed into about six months.
"But we have heard of the surprising phenomenon of isolated cases of greatly accelerated evolution in viruses in Britain. As much evolution occurred in that one individual in England as had occurred in the millions of other infections.
"Our theory proposes that a similar evolution was happening inside the lungs of miners following the mystery disease in 2012 and argues that the virus leaked from a medical sample obtained from the miners infected by the outbreak."
When scientists returned to the mine at the end of 2012, they found samples of a pathogen that came to be known as the "Mojiang virus".
The Mojiang virus is found in rats and unrelated to SARS-CoV-2, and it was not confirmed whether it was behind the miners’ illness.
Since then, China’s top bat coronavirus researcher, the Wuhan Institute of Virology's (WIV) Shi Zhengli, has said that the workers' pneumonia-like symptoms were caused by a fungal infection and that there was no sign they had been infected with SARS-CoV-2.
But the case of the mineworkers has been used by those supporting the idea that a coronavirus very similar to SARS-CoV-2 could have been infecting humans as early as 2012.
The new theory by Dr Latham suggests that the evolution from a virus such as RaTG13 could have occurred far more quickly inside the body of a miner.
Dr Latham said: "We know that coronaviruses were diverse and abundant near the mine, and we know that some of the miners underwent lengthy hospitalisations.
"Their treatment lasted six months and allowed the evolution of novel adapted human coronaviruses.
"We know many medical samples were sent to the Wuhan institute of Virology, so the question is,what was in the samples, and what was done with any viruses that were found?"
China and WIV have strenuously denied allegations that coronavirus escaped from a Wuhan laboratory.
To get all the latest news and gossip, click here to subscribe to our newsletter
