A U.S. intelligence report obtained by The Wall Street Journal says that in November 2019, three researchers from the Wuhan Institute of Virology in China became sick with a flu-like illness and they had to seek hospital care, according to Medscape.

The findings of this report have been raising concerns about whether the new coronavirus (SARS-CoV-2) escaped from the lab, according to the newspaper.

The Wall Street Journal reported that several researchers at the lab became sick at the end of 2019 “with symptoms consistent with both COVID-19 and common seasonal illness.”

Health authorities have been expressing concerns over the number of researchers who became sick, the timing of their illnesses, and the fact that they had to seek hospital care for their symptoms.

Some officials said the supporting evidence is strong, some said it was weak, while others said it should be investigated.

However, the report does not explain why those researchers got sick or what their diagnosis was.

Earlier this year, the Trump administration released a fact sheet from the State Department, stating that several Wuhan researchers were sick, but it did not say they were hospitalized.

The first case of COVID-19 was reported in Wuhan, China, on December 8, 2019, per CNN.

Reacting to the U.S. intelligence report, the Wuhan National Biosafety Lab, which is associated with the Wuhan Institute of Virology, said it is a complete lie, according to CNN.

Dr. Yuan Zhiming, director of the biosafety lab, told Global Times, “I’ve read it. It’s a complete lie. Those claims are groundless. The lab has not been aware of this situation, and I don’t even know where such information came from.”

China’s Foreign Ministry also denied the report and accused the U.S. of “hyping up the lab leak theory,” according to CNN.

Zhao Lijian, a spokesman for the ministry, said, “Through field visits and in-depth visits in China, the experts unanimously agreed that the allegation of lab leaking is extremely unlikely.”

Even the World Health Organization (WHO) looked into the origins of the pandemic and said the risk of a lab accident was “extremely low,” according to CNN.

In February, Dr. Peter Daszak, a UK-based disease ecologist who worked with the WHO team, told CNN that there was “really still no evidence” that the pandemic started in a lab, adding that the lab was “very well-run” and the researchers showed no evidence of COVID-19 antibodies.

Earlier this month, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases (NIAID), said he was “not convinced” the novel coronavirus developed naturally.

He said, “I am not convinced about that. I think that we should continue to investigate what went on in China until we find out to the best of our ability what happened.”

Dr. Fauci explained, “Certainly, the people who investigated it say it likely was the emergence from an animal reservoir that then infected individuals, but it could have been something else, and we need to find that out. That’s the reason why I said I’m perfectly in favor of any investigation that looks into the origin of the virus.” The article was published on Medscape Medical News.