Former Deputy National Security Adviser Matt Pottinger on Sunday, Feb. 21, addressed the origin of the virus that caused the Wuhan virus pandemic, saying that evidence pointing to it originating as a result of human error in a Chinese lab far outweighs other theories about its origins.

During an interview on CBS News’ “Face the Nation,” Pottinger said, “If you weigh the circumstantial evidence, the ledger on the side of an explanation that says that this resulted from some kind of human error, it far outweighs the side of the scale that says this was some natural outbreak.”

“We have very strong reason to believe that the Chinese military was doing classified animal experiments in secret in that same lab, going back to at least 2017,” Pottinger added, according to Daily Caller.

Pottinger insisted that there were compelling reasons to point out that several of the researchers working inside the Wuhan Institute of Virology contracted an illness with symptoms similar to the coronavirus, but before the first documented cases of the disease were known.

President Biden’s national security adviser, Jake Sullivan, indicated in an interview with CBS that the latest report by the WHO team of investigators on the origins of the virus in China was unreliable.

Sullivan accused the Chinese Communist Party (CCP) of withholding raw data from investigators, calling on the WHO to “step up” its investigation.

“They’re about to come out with a report about the origins of the pandemic in Wuhan, China, that we have questions about,” Sullivan said.

“We do not believe that China has made available sufficient original data into how this pandemic began to spread both in China and then eventually around the world,” the Biden administration official added.

The WHO fact-finding mission ruled out at the outset a possible artificial origin of the virus, stating, “The laboratory incidence hypothesis is extremely unlikely to explain the introduction of the virus into the human population,” according to team leader Peter Embarek.

Instead, the research turned to investigating other possible origins of the virus, such as the theory that it jumped from an animal species to humans at one of the Wuhan food markets or that it was transmitted from abroad through frozen food.

Pottinger also pointed out that the WHO still has a lot to answer for, accusing the U.N. agency of making all sorts of false or misinformed claims about the virus, such as the claim it made in January last year stating that the virus was not transmitted from person to person.

Meanwhile, several scientists from leading institutions around the world are warning about the recently concluded WHO investigation in China, claiming that it was an incomplete and unreliable investigation into the origins of the SARS-Cov-2 (CCP Virus) virus.

According to Just the News, researchers questioned the WHO’s conclusions about the China investigation by asserting that researchers have not been granted sufficient access to the Wuhan lab to determine whether the virus emerged during a lab accident in the last few months of 2019.

University of Innsbruck bioengineer Rossana Segreto told Just the News that it is “for sure more likely that SARS2 leaked from a lab than jumped from a natural host.”

Segreto said that according to preliminary research she participated in, “several characteristics of SARS-CoV-2 taken together are not easily explained by a natural zoonotic origin hypothesis.”

Among the characteristics that the Segreto talked about are the “low rate of evolution in the early phase of transmission, the lack of evidence of recombination events and ‘a novel furin cleavage site insert,'” referring to an enzyme involved in the measurement of body functions.

Colin Butler, honorary professor at the National Center for Epidemiology and Population Health at the Australian National University, said the laboratory leakage theory is “highly plausible,” indicating that if there was sufficient transparency from the Wuhan Institute of Virology, that is detailed records ‘going back for a decade or more,’ would be sufficient that there would be no need for the WHO to visit China.