The virologist behind the most notorious lab-generated virus in history played an undisclosed role in persuading the world that the COVID-19 pandemic did not emerge from similar research, according to several sources.

The new revelations concern a correspondence in Nature Medicine called “The proximal origin of SARS-CoV-2 ” that argued it was improbable for the novel coronavirus to have emerged from research.

Though the letter was published online in March 2020, its legacy endures. It has been cited by thousands of news articles and Wikipedia pages declaring the lab leak theory — the theory that COVID-19 emerged from a research related incident at a coronavirus lab at the pandemic’s epicenter — to be false and a conspiracy theory. The letter made the highest impact of any paper published about medical science in 2020, the year the COVID-19 pandemic burst onto the globe, according to Altmetric.

The high impact work has brought the authors prestige, and they continue to publish articles supporting the theory that SARS-CoV-2 emerged naturally in wildlife and act as trusted messengers on the origins of the pandemic in the media.

But a separate trio of virologists had a secret influence on the historically popular paper. They include a virologist whose name is synonymous with risky research and his boss, according to emails obtained under the Freedom of Information Act and statements by the authors.

The paper’s esteemed authors cribbed central ideas from a controversial gain-of-function practitioner without credit, obscuring his role and influence.

The episode is just the latest development calling into question the credibility of two publications in prestigious journals that marginalized the lab leak theory as a conspiracy theory very early in the pandemic, before much data had emerged. For many virologists and reporters, the “conspiracy theory” label has stuck, even as new information has emerged about the authors’ concealed concerns about viral engineering and scientific collaborations in Wuhan.

Now, emails and interviews make clear that perhaps the most controversial gain-of-function virologist in history had a behind-the-scenes role in persuading the world that SARS-CoV-2 was not engineered.

Marion Koopmans, head of virology at the Erasmus Medical Center in the Netherlands, and Ron Fouchier, her deputy, were key to some of its central arguments. Christian Drosten, director of the Institute of Virology at the Charité Hospital in Berlin, also made the case that SARS-CoV-2 could not have been engineered.

A review of their scientific publications show that they have deeper experience working with coronaviruses in the lab than the virologists publicly credited as co-authors of the article.

But Koopmans and Fouchier also had competing interests.

Erasmus Medical Center partners with EcoHealth Alliance, a virus hunting project that worked closely with the Wuhan Institute of Virology, a lab at the pandemic’s epicenter.

Fouchier’s involvement in particular may have caused a stir had it been apparent when the piece first published online in March 2020.

In 2011, Fouchier garnered worldwide notoriety when he generated an airborne strain of an avian flu with an estimated 60 percent fatality rate. The experiment demonstrated that a few mutations could trigger airborne transmission in humans, according to Fouchier’s institution.

The New York Times editorial board deemed it “an engineered doomsday.”

Some scientists expressed concerns about lab accidents and rogue copycats, and said that the experiment risked setting off an apocalyptic pandemic. Virologists concerned about spillover cautioned that censoring the project could impede scientific progress.

Fouchier was criticized for shifting statements about the risk and underestimating the chances of an accident.

The Fouchier experiment was among the most infamous controversies in virology — until the origins of COVID-19 debate.

But Fouchier’s hidden influence on the debate about a possible lab origin of COVID-19 via the Nature Medicine paper remained unknown for more than a year and has been largely ignored.

David Fisman, a University of Toronto epidemiologist who is critical of the riskiest gain-of-function research, said that the name “Fouchier” has for him been “synonymous with irresponsible lab science” since the bird flu experiments made headlines a decade ago.

“I think it would have made my spidey senses tingle had Fouchier been a listed author, knowing about his past work and apparent inability to consider the ethical dimensions of risky research,” he continued. “With respect to hiding Fouchier’s contribution: that’s also concerning, and I think fits into a broader pattern of non-transparency and even subterfuge.”

The uncredited virologists were purportedly so central to the paper that rumors circulated in the scientific community that the paper had initially been rejected by Nature — a more prestigious and higher impact journal — due to plagiarized ideas, a new email released under a FOIA lawsuit suggests.

Nature declined to comment.

“For confidentiality reasons, we cannot discuss the details of the review process for any manuscript that may or may not have been submitted to Nature,” said Michael Stacey, a spokesman for the journal.

Alina Chan, a postdoctoral researcher at the Broad Institute who has been critical of the article, has called for disclosure of Fouchier’s contributions, as well as other more obvious conflicts of interest.

“The Proximal Origin letter still does not acknowledge that one of its authors collaborated with Wuhan scientists to study novel SARS-like viruses and that the letter had input from gain-of-function advocates and funders of the Wuhan Institute of Virology,” Chan said in a tweet.

The concealed contributions of Fouchier, Koopmans and Drosten, have now been confirmed by multiple participants and are backed by other emails.

By now, the paper’s genesis is well known: In late January and early Feburary, Wellcome Trust Director Jeremy Farrar, concerned the burgeoning pandemic had spilled out of Wuhan’s coronavirus labs, organized a private teleconference with top virologists and leaders of the National Institutes of Health, including Anthony Fauci.

Scripps Research virologist Kristian Andersen and University of Sydney virologist Edward Holmes presented concerns to the group that SARS-CoV-2 bore markers of engineering, but were met with resistance by other scientists on the call.

“There was derision down the phone line,” Farrar recounted in his memoir.

Fouchier, Koopmans and Drosten “could not countenance the fact it might be a lab escape, for good reason: if someone was engineering a coronavirus, they wouldn’t use some random bat virus,” he wrote.

This account was corroborated by Holmes in a recent podcast interview.

Farrar had invited “most importantly some people who know something about coronaviruses, which is really not me so much,” Holmes said.

“People like Ron [Fouchier] very correctly pointed out … you would use a standard lab background and this is not a standard lab background,” Holmes continued. “And they gave a whole set of very cogent points about what you would do if you were going to do this.”

A separate email from then-National Institutes of Health Director Francis Collins at the time indicates that the debate may have gotten ugly.

Collins wrote shortly after the teleconference that arguments against a lab origin were presented by Fouchier and Drosten “with more forcefulness than necessary.”

Koopmans, Drosten, Fouchier, Andersen and Holmes did not reply to emailed questions.

The argument that the Wuhan Institute of Virology would have only worked with published, well known viruses in the lab has been undermined by new information about the scope of the coronavirus hunting underway and the lab’s interest in working with reverse genetics on unknown viruses.

Richard Ebright, professor of chemistry and chemical biology at Rutgers University and laboratory director at the university’s Waksman Institute of Microbiology, said that it may be difficult for virologists who championed relatively unrestrained gain-of-function research in the debate over Fouchier’s work a decade ago to entertain the possibility that COVID-19 may have resulted from a lab accident.

“For persons who had argued strenuously that the probability that a GOF-research-related accident could cause a pandemic is nearly zero over the time scale of the five to ten decades, it is difficult to acknowledge the possibility that a GOF-research-related accident already may have caused a pandemic in the present decade,” Ebright said. “For persons who make their living performing GOF research — particularly those who participated in the specific GOF research project that may have caused the pandemic — it is even harder.”

Ebright also criticized government officials who have funded gain-of-function work over the years, including outgoing National Institute of Allergy and Infectious Diseases Director Anthony Fauci. Fauci has encouraged gain-of-function research as the longtime director of the NIH’s infectious disease institute and funded coronavirus work performed in collaboration with the Wuhan Institute of Virology. Some of this funding was found to be out of compliance with NIH’s own policies.

“And, for public officials who, through negligence or misfeasance, violated federal policies to fund GOF research without the risk-benefit review mandated by federal policies — particularly those who violated federal policies to fund the specific GOF research project that may have caused the pandemic — it is even harder,” Ebright concluded.