The coronavirus most likely emerged in bats before spreading to humans through another animal, according to a report to be released by the World Health Organization on Tuesday, offering some clues on a question that has become politically fraught amid accusations of interference from Beijing.

According to the report on the origin of the pandemic, which was obtained by The New York Times in advance of its release, a team of experts who recently visited the Chinese city of Wuhan, where the coronavirus was first detected in late 2019, also dismissed the idea that the virus might have leaked accidentally from a Chinese laboratory as “extremely unlikely.”

Officials in the United States and elsewhere have expressed concern about China’s efforts to reshape the narrative about the outbreak in Wuhan, which the authorities initially tried to conceal.

Critics have assailed the inquiry by the W.H.O. team as insufficient, saying the global health agency has been too deferential to Beijing. Chinese scientists, many of whom are affiliated with the government, helped oversee the inquiry, and the report was repeatedly delayed amid delicate negotiations with Chinese officials. For months, China sought to delay the visit of the investigators in an apparent attempt to avoid scrutiny of its early mistakes in handling the pandemic.