The researchers at the Shanghai Institute for Biological Sciences suggested that the virus existed on the Indian subcontinent before the Wuhan outbreak in December last year.
"Our result shows that Wuhan is not the place where human-to-human SARS-CoV-2 transmission first happened," they wrote.
"Both the least mutated strain's geographic information and the strain diversity suggest that the Indian subcontinent might be the place where the earliest human-to-human SARS-CoV-2 transmission occurred, which was three or four months before the Wuhan outbreak."
The study which bases its findings on research into strains of the virus provided by 17 different countries was posted on SSRN.Com, the preprint platform of the medical journal The Lancet, on November 17.
It challenges general orthodoxy among scientists that the virus originated in the wet markets of Wuhan.
The research, led by Dr Shen Libing, claimed the traditional approach to tracing the origin of Covid-19 strains did not work as it used a bat virus discovered in Yunnan, southwest China, several years ago.
Scientists use this as an ancestral reference to examine the evolutionary history of the bug but the bat virus is not the human virus' ancestor.
So, the researchers claim this prevents scientists from tracing the origins of the pandemic and they used a new method that involves counting the number of mutations in each viral strain.
The Chinese scientists claim that the strains with the most mutations have been around for a longer time, and those with fewer mutations are closer to the original ancestor of Covid-19.
Their paper claims that the least mutated strain was found in eight countries – Australia, Bangladesh, Greece, the US, Russia, Italy, and the Czech Republic.
It also says that the area of the first outbreak should have the greatest genetic diversity, and cites India and Bangladesh.
The researchers propose that India's young population, extreme weather, and drought created the necessary conditions for the virus to jump to humans.
However, the findings are still a preprint and are yet to be peer-reviewed. So, they should not be seen as established conclusions.
Indian scientists have also challenged the findings of the study, says The Sun.
Mukesh Thakur, an Indian virologist, told the South China Morning Post the conclusions were a "misinterpretation."
And Marc Suchard, professor in human genetics and biostatistics at UCLA, said that the "arbitrary collection" of viral strains used was "unlikely to yield the progenitor."
"The method holds great promise, but it comes with considerable uncertainty," Marc said.