The coronavirus may have been lying dormant across the world until emerging under favourable environmental conditions, rather than originating in China, an expert has claimed.

Dr Tom Jefferson, from the Centre for Evidence-Based Medicine (CEBM) at Oxford University, has pointed to a string of recent discoveries of the virus’s presence around the world before it emerged in Asia as growing evidence of its true origin as a global organism that was waiting for favourable conditions to finally emerge.

Traces of Covid-19 have been found in sewage samples from Spain, Italy and Brazil which pre-date its discovery in China.

The explanation could only be that these agents don’t come or go anywhere. They are always here and something ignites them, maybe human density or environmental conditions, and this is what we should look for

In an interview with The Daily Telegraph, Dr Jefferson has called for an investigation into how and why the virus seems to thrive in environments such as food factories and meatpacking plants.

Along with CEBM director Professor Carl Heneghan, Dr Jefferson believes this could potentially uncover new transmission routes, such as through the sewerage system or shared lavatory facilities.

He told the paper: “Strange things like this happened with Spanish Flu. In 1918, around 30% of the population of Western Samoa died of Spanish Flu and they hadn’t had any communication with the outside world.

“The explanation could only be that these agents don’t come or go anywhere. They are always here and something ignites them, maybe human density or environmental conditions, and this is what we should look for.

“There is quite a lot of evidence of huge amounts of the virus in sewage all over the place, and an increasing amount of evidence there is faecal transmission.

“There is a high concentration where sewage is four degrees, which is the ideal temperature for it to be stabled and presumably activated. And meatpacking plants are often at four degrees.

“These outbreaks need to be investigated properly.”