GENEVA — A World Health Organization (WHO) expert group tasked with investigating the origins of the COVID-19 pandemic has released its final report, concluding that the origins of the virus remain inconclusive despite more than three years of scientific work.

The group, chaired by Marietjie Venter, stated that most available data still points to a natural spillover of the virus from animals to humans, echoing conclusions from the WHO's earlier 2021 mission that suggested transmission from bats to humans via another animal host.

However, the group said it was unable to access sufficient data from China to fully assess the possibility of a lab-related incident.

“Despite repeated requests, key genetic sequences and biosecurity details were not provided by Chinese authorities,” Venter said at a press briefing.

“Therefore, the hypothesis of a laboratory accident could neither be confirmed nor excluded. It remains speculative and unsupported by scientific evidence.”

The group also found no indication that the virus had been circulating outside of China before December 2019, and there was no evidence that SARS-CoV-2 was deliberately manipulated in a lab.

The report, which comes after years of geopolitical tension over the origins of the virus, highlighted internal disagreements within the expert group.

One member resigned prior to publication and three others requested their names be removed from the final document.

WHO Director-General Dr. Tedros Adhanom Ghebreyesus reiterated that understanding the origins of the pandemic is a “moral imperative,” citing the more than 20 million lives lost, the trillions of dollars in economic disruption, and the global upheaval caused by COVID-19.

The findings also reflect longstanding challenges in international scientific cooperation. An earlier investigation by the Associated Press revealed that China halted key efforts to trace the virus' origin in early 2020, and that the WHO missed early chances to launch a comprehensive probe.

While U.S. officials, including President Donald Trump, have long promoted the lab-leak theory, a 2021 U.S. intelligence review concluded there was not enough evidence to support or dismiss it.

Chinese officials continue to reject the notion of a lab origin and argue that origin-tracing efforts should be expanded to other countries.

Scientists involved in the WHO-led investigation have also identified a list of animals that could have served as intermediate hosts, including raccoon dogs, civet cats, and bamboo rats. — Agencies