but the scientists had more to say about what they hadn't found than what they had. it has not been possible to pinpoint any animal species as a potential reservoir for this disease, and it doesn't look like there was wide circulation of the virus in any animal species in the country. china's wet markets were once thought to be the prime suspect, where the virus was most likely to havejumped from animals to humans. this market, linked to some of the earliest cases, was a particular focus, but with animal tests said to be negative, the team has come up with another theory — frozen food. and an idea china itself has been promoting in recent months. the virus, they suggest, may have travelled to wuhan on imported frozen produce. the who arrived here insisting this was going to be all about the science,