Coronavirus could have spread among humans 'for years or even decades' before it was detected in Wuhan, a team of scientists have claimed.
They believe a strain of coronavirus may have jumped from animal to human as long as a decade ago - and before it was capable of causing the disease in people.
The findings have been published the scientific journal Nature Medicine after a team of experts analysed the pandemic sweeping the globe.
Dr Francis Collins, director of the US National Institute of Health, said "...as a result of gradual evolutionary changes over years or perhaps decades.