An expert from the WHO team that concluded its research trip in Wuhan a few days ago on Sunday suggested that it's important to look into the pandemic from both inside and outside China. 

Speaking on British TV show the Andrew Marr Show, Professor John Watson, England's former deputy chief medical officer, said the various bits of information about the way viruses live in the animal reservoirs and suggested that China is "by no means necessarily the place where the leap from animals to humans took place." 

He said on the show that the pandemic most likely started with an infection in an "animal reservoir," which was then passed on to humans through an "intermediate host," Daily Mail online reported. The animal reservoir consists of wild or domesticated animals infected by pathogens.

He suggested the virus that was passed to animals then to humans could occur outside the country's borders, "I think we need to ensure that we are looking beyond the borders of China, as well as within China." 

Watson said the team's visit was not a "one-off" and that the WHO sees it as "the start of a process that's going to take really quite a while," according to the website. 

Peter Embarek, head of the WHO mission, also commented on how complex the research is. "Illustrating how complicated this work is, it is not possible to come up with all answers after a few weeks of study,"  he said.

"When we talked to one of first cases, you immediately think they must have some very special habits, hiking in the mountains, keeping wild pets at home; instead you realize they are very much like us – spending days on the internet, same jobs, activities and sports as many of us do." 

"This needs to be done in a systematic way, building bit by bit to get answers; that is what we will continue to do with our Chinese colleagues," he said.