President Biden on Tuesday received a classified report from the intelligence community that was inconclusive about the origins of the novel coronavirus, including whether the pathogen jumped from an animal to a human as part of a natural process, or escaped from a lab in central China, according to two U.S. officials familiar with the matter.

The intelligence community will seek within days to declassify elements of the report for potential public release, officials said.

The assessment is the result of a 90-day sprint after Biden tasked his intelligence agencies in May to produce a report “that could bring us closer to a definitive conclusion” on the origins of a virus that has killed more than 4 million people globally and wrecked national economies. But despite analyzing a raft of existing intelligence and searching for new clues, intelligence officials fell short of a consensus, said the officials, who spoke on the condition of anonymity because the report is not yet public.

The debate over the virus’s origins has become increasingly rancorous since former president Donald Trump said last year that the virus originated in a Chinese lab. Efforts to understand the virus’s provenance have been complicated by Chinese authorities’ steadfast refusal to allow a more intensive inquiry by international investigators.

Biden’s directive came after he received a May report from the agencies saying that they had “coalesced around two likely scenarios” but had not reached a conclusion. He disclosed that two agencies leaned toward the hypothesis that the virus emerged from human contact with an infected animal, while a third leaned toward the lab accident scenario.

The leader of the intelligence community, Director of National Intelligence Avril Haines, cautioned in June that the agencies might not solve the mystery. “We’re hoping to find a smoking gun,” she told Yahoo News in an interview. But, she said, “it’s challenging to do that,” adding that “it might happen, but it might not.”

The review involved dozens of analysts and intelligence officials across multiple agencies, Haines told Yahoo. She said she deployed “red cells,” or groups to test analysts’ assumptions and ensure the intelligence is scrutinized from every angle.

Another official said the intelligence community is “not necessarily best equipped to solve this problem,” which is fundamentally an issue of science. Although spy services are “positioned to collect on a range of foreign actors,” the official said, they are not necessarily poised to dive into global health data sets.

Biden himself, in his first visit to the Office of the Director of National Intelligence in July, voiced the need for a more robust group to track pathogens. “You’re going to have to increase your ranks with people with significant scientific capacity relative to pathogens,” he said at the time.

Officials in the Biden administration hammered China’s lack of transparency ahead of a World Health Organization report on the origins of the coronavirus. (JM Rieger/The Washington Post)

Many scientists familiar with the origin debate have been skeptical that the 90-day review would settle it, and some have said the inquiry could require years of research.

“We should not even be thinking about closing the book or backing off, but rather ratcheting up the effort,” David Relman, a Stanford University microbiologist who has pushed for a broad investigation of all origin hypotheses, said late Tuesday in an email.

The notion that the virus may have escaped from a lab got sharply increased interest this spring after 18 scientists wrote a letter to the journal Science in May saying that all possible origins needed to be investigated, including a laboratory accident.

Proponents of that theory point to classified information, first disclosed in the waning days of the Trump administration, that three unidentified workers from the Wuhan Institute of Virology — one of the world’s preeminent research institutions studying coronaviruses — went to the hospital in November 2019 with flu-like symptoms. In China, people visit the hospital for routine and mild illnesses.

Throughout 2020, that hypothesis became enmeshed in election-year politics. Trump’s assertion that the virus emanated from a lab came as he and other administration officials were blaming China for the global outbreak and trying to deflect attention from their botched handling of the virus at home.

Many scientists, however, noted that viruses have a long history of jumping from animals to humans. There are many plausible scenarios in which that might have occurred, including the possibility the virus spread from wild and domestically raised animals sold in crowded markets. Many early cases were clustered around a seafood market where traces of the virus were later detected on surfaces.

That zoonosis theory was bolstered by a June 7 report, published in the journal Nature, documenting 38 species of animals sold in 17 markets in Wuhan before the pandemic. The authors said many of the animals suffered from poor hygiene and were known to carry zoonotic diseases.

“We now know for sure that [coronavirus] susceptible animals were in fact sold at the markets in Wuhan, which changes the calculus tremendously,” Robert Garry, a Tulane University microbiologist who strongly supports the zoonosis theory, said in an email.

Experts in viral genome evolution also determined that the novel coronavirus almost certainly was not engineered as a bioweapon because it has several naturally occurring features seen in many other coronaviruses. But even scientists favoring a natural origin have said that without definitive evidence of animal-to-human transmission, it is not possible to rule out the possibility that a laboratory accident led to the outbreak.

And many questions remain unanswered. The animal that carried this virus before it infected people has not been identified — a process that has taken years in previous disease outbreak investigations. Nor have the lab-leak advocates found any direct evidence that SARS-CoV-2 was inside a laboratory in Wuhan before the pandemic, although the lab has not released its records, which have been sought by scientists and governments around the world.

A delegation of investigators from the World Health Organization made a brief visit to the Wuhan laboratory in February and later declared that there were multiple possible origins, with a natural zoonosis most likely and a lab leak “extremely unlikely.”

But the WHO director general, Tedros Adhanom Ghebreyesus, undercut that conclusion, saying it would be premature to rule out the lab-leak theory. The WHO effort was also criticized by some international scientists and researchers, who called for further investigation.

White House press secretary Jen Psaki on Monday said the public would be told the report’s outcome. “I don’t know what format that will take at this point in time,” she said.