A group of scientists have released three studies of which two have traced the outbreak to a massive market in Wuhan that sold live animals, among other goods.

The third study suggested that the coronavirus spilled over from animals, probably those sold at the market, into humans at least twice in November or December 2019.

The studies were based on genetic analyses of Covid samples collected from the Wuhan market and infected people from December 2019 to January 2020.

They also made geolocation analyses by connecting the samples to the section of the market where live animals were sold.

The reports, yet to be published in a scientific journal, were posted on Zenodo, an open-access research repository operated by CERN. Kristian Andersen, a virologist at the Scripps Research Institute in La Jolla, California, and an author on two of the reports, said, "This is extremely strong evidence."

"When you look at all of the evidence together, it's an extraordinarily clear picture that the pandemic started at the Huanan market," The New York Times quoted Michael Worobey, an evolutionary biologist at the University of Arizona and a co-author of both studies, as saying.

However, the studies have not pointed towards the type of animal responsible for the spread of virus to humans.

Andersen speculates that the culprits could be raccoon dogs, a squat dog-like mammal used for food and for their fur in China, Nature reported. According to virologists, the new evidence has, however, has not ruled out an alternative hypothesis that claims the market could just have been the "location of a massive amplifying event".

In January 2020, Chinese authorities had identified the Huanan market as a potential source of the coronavirus outbreak. Later in 2021, the World Health Organization (WHO) conducted an investigation in Wuhan and suggested that the virus was probably transmitted from bats to humans but via some other animal.

(With UNI inputs)