A new analysis of genetic information conducted by an international group of researchers has found evidence to suggest that COVID-19 originated from infected animals sold at a market in Wuhan, China.

As first reported by The Atlantic, French evolutionary biologist Florence Débarre recently uncovered genetic data from the global virology database GISAID. The data had been submitted by Chinese researchers who collected the genetic sequences from the Huanan Seafood Wholesale Market, which has been scrutinized as being the epicenter of the COVID-19 pandemic.

Despite the name, thousands mammals were found to have been sold at the market, where they were kept in cramped and unhygienic spaces.

The genetic data suggested that raccoon dogs being sold at the market could have been carrying and shedding the SARS-CoV-2 virus at the time. The analysis, which is not conclusive, is being led by researchers Kristian Andersen, Edward Holmes and Michael Worobey.

In communications with Atlantic writer Katherine J. Wu, Andersen said they did not know if raccoon dogs were the immediate hosts of the virus to infect humans but said they were “high” on his list of potential hosts, among others.

These findings, which have not been published, were presented to the World Health Organization’s (WHO) Scientific Advisory Group for the Origins of Novel Pathogens on Tuesday. The journal Science noted that the research submitted to GISAID has since been removed at the request of the original submitters.

This new evidence adds further fuel to the ongoing lab-leak versus natural origins debate, which has recently gained new momentum with the conclusion from the U.S. Department of Energy that COVID-19 originated from a Chinese research lab.

Proponents of the lab-leak theory have fervently argued that it cannot be a coincidence that COVID-19 was first detected in Wuhan, near the Wuhan Institute of Virology, where research on coronaviruses was being conducted.

However, opponents to this theory argue that there isn’t enough evidence to suggest there was a lab leak and also point out that previous outbreaks of coronaviruses have had confirmed animal sources.

A consensus on COVID-19’s origins is far from being reached, and some researchers question whether a conclusive answer will ever come forward, particularly with China’s continued resistance to providing further data.

In its 2021 report on the potential origins of COVID-19, the WHO gave likely credence to the animal transmission theory, pointing to bats or minks as possible reservoirs for the disease. The organization stated at the time that further information on supply chain of the Huanan market would be needed.

Tracking down the origins of a virus often takes years, but previous efforts have traced back to animal origins. Researchers have linked human infections of MERS, a virus in coronavirus family that was first reported in 2012, to interactions with infected camels.