A joint study from the World Health Organization (WHO) and Chinese scientists on the origins of COVID-19 said it is likely that it originated from bats and has spread to another animal before passing it to the human population.

The 123-page study also concluded that it is unlikely that the virus leaked from a Wuhan lab, which is a theory being reviewed by some experts even though it is based on circumstantial evidence, NBC News reported.

The findings resulted from the joint study conducted in China last month to investigate the virus' origin.

"All available evidence suggests the virus has an animal origin and is not manipulated or constructed virus in a lab or somewhere else," WHO spokeswoman Fadela Chaib said as Fox News reported.

Researchers recently discovered six additional coronaviruses in bats, and there may be more coronavirus yet-to-be-discovered in the said mammals.

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Origin of COVID-19 

The outbreak was known to have first occurred in December 2019. However, some reports noted that the disease's first case could be traced back to November 2019.

Meanwhile, other critics said that the inquiry was insufficient as many Chinese scientists involved are affiliated with government-run institutions. Also, investigators did not have full access to lab records and raw data.

WHO's report recommended additional research for those and other scenarios, including retrospective studies of the earliest known cases linked to the seafood market in Wuhan, China. The report also said it is not clear whether that was the initial source of the outbreak.

Lab Leak Narrative

The lab leak hypothesis was supported by former President Donald Trump and was recently touted by former director of the Centers for Disease Control and Prevention, Dr. Robert Redfield.

"I am of the point of view that I still think the most likely etiology of this pathogen in Wuhan was from a laboratory. Escaped," Redfield said in a report.

However, the nation's top infectious disease expert, Dr. Anthony Fauci, said that Redfield was simply expressing an opinion.

Meanwhile, U.S. Secretary of State Antony Blinken said that they had real concerns about the methodology and the process that were done in the report. Blinken said this includes the fact that Beijing helped wrote the report, Telegraph reported.

Foreign Ministry spokesperson Zhao Lijian rejected the criticism, saying that the U.S. was trying to exert political pressure on the WHO expert group members.

He then asked when the U.S. will invite the WHO experts to visit the U.S. and conduct work to trace the source and open the Fort Detrick laboratory for international experts to tour.

The U.S. intelligence has earlier assessed that the virus may have leaked from a lab in Wuhan. Redfield also claimed that it is not unusual for workers to be infected with a respiratory virus, especially if they are working on it.

Some reports echoed the same sentiments, saying humans could become infected in laboratories with limited biosafety, poor laboratory management practice, and negligence.

READ MORE: Experts Suggest Novel Coronavirus Originated From Lab in Wuhan 

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