evidence: The hunt for the origin of the COVID-19 pandemic has new leads. Researchers have identified half a dozen animal species that could have passed SARS-CoV-2, the coronavirus that causes COVID-19, to people, by reanalysing genomes collected from an animal market in Wuhan, China1. The study establishes the presence of animals and the virus at the market, although it does not confirm whether the animals themselves were infected with the virus. [...] The search for how the pandemic began has been hugely controversial. Most researchers say the virus originated in bats that infected people, most probably through an intermediate animal, as has happened with other pathogens that have emerged in humans. But a lack of strong evidence for an intermediate host has led some researchers to argue that the virus could have escaped — deliberately or accidentally — from the Wuhan Institute of Virology. [...] When researchers at the China CDC published their analysis in Nature last April, they reported samples that contained SARS-CoV-2 and came from wild animals in the market, most notably raccoon dogs (Nyctereutes procyonoides), which are susceptible to SARS-CoV-2 and can spread the virus to other animals. But the team noted that there was no way to establish that the animals were infected with SARS-CoV-2. Even if they were infected, they could have caught the infection from a person who brought the virus to the market, which leaves open the possibility that the market was not the site of the pandemic’s emergence.