A Chinese scientist partially funded by U.S. grants who was working in Wuhan was one of three researchers who fell sick with a mystery illness early on in the coronavirus pandemic, a former U.S. official confirmed Tuesday. 

Ben Hu had been working at the Wuhan Institute of Virology when he and the other two scientists were sickened with an unspecified illness in late 2019, potentially lending credibility to the theory that the pandemic could have originated from a lab leak rather than from a wild animal market in Wuhan. 

Hu had been researching coronaviruses at the lab when he became sick with a disease that mirrored the symptoms of COVID-19, U.S. intelligence reports said, the Wall Street Journal first reported. 

Some of Hu’s projects were funded by U.S. grants, a Freedom of Information Act by the nonprofit White Coat Waste Project revealed, according to the Journal.

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Between 2014 and 2019, $1.4 million was granted to the lab in Wuhan by the U.S. Agency for International Development (USAID) and the National Institutes of Health, the Government Accountability Office reportedly said in a report last week, The grants ended in 2019.

Fox News Digital has reached out to NIH and USAID. 

Hu’s projects included in the funding were one studying animal viruses that could transfer to humans and cause a pandemic and one researching bat coronaviruses. 

Robert Kadlec, a former Health and Human Services Department official, told the Journal that Hu and the other two scientists "published on SARS-related coronavirus experiments done at inappropriately low biosafety settings that could have resulted in a laboratory infection." 

Along with Hu, the other scientists were identified as Yu Ping and Yan Zhu. All three of the researchers lived. 

Ping had written a report on coronaviruses found in bats prior to becoming ill, the Journal reported. 

The researchers were first identified in a Substack article last week, citing U.S. government sources, and referring to the scientists among "patients zero." 

The Substack article said the revelation "strengthens the case that the SARS-CoV-2 virus accidentally escaped from the Wuhan Institute of Virology." 

A Wuhan man who fell ill on Dec. 8, 2019, was previously identified by Chinese authorities as the first official case. Hu and the other two scientists became sick in November. 

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From the beginning of the pandemic, China has lacked transparency about the virus. 

"The lack of data disclosure is simply inexcusable," Maria Van Kirkhove, an epidemiologist with the World Health Organization, wrote in an April op-ed for the journal Science. "The longer it takes to understand the origins of the pandemic, the harder it becomes to answer the question, and the more unsafe the world becomes."

President Biden signed a law in March that could allow more information on the pandemic and its origins to be declassified – as early as this week. 

Neither experts nor the U.S. government is sure whether the pandemic originated from a lab leak or not. 

The Wuhan Institute of Virology told the Journal it had nothing new to say. Fox News Digital has reached out for comment. 

Kansas Sen. Roger Mashall, a Republican, said the revelations show a need for greater scrutiny over U.S. grants.

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"Not only should we better monitor the scientists and types of research we support but we must reform the U.S. global research grant administration to ensure oversight, transparency, and accountability," he said, according to the Journal. 

Fox News' Rich Edson contributed to this report