"Peter Ben Embarek, the head of the World Health Organization (WHO) mission, said it was "extremely unlikely" that the virus leaked from a lab in the city of Wuhan."

The investigation could now focus on South East Asia, one expert said.

Dr Embarek said work to identify the origins of Covid-19 pointed to a "natural reservoir" in bats, but it was unlikely that this happened in Wuhan.

He said identifying the animal pathway remained a "work in progress", but that it was "most likely" to have crossed over to humans from an intermediary species.

The experts also said there was "no indication" that the virus was circulating in Wuhan before the first official cases were recorded there in December 2019.

Liang Wannian, an expert with China's Health Commission, said Covid-19 could have been in other regions before it was detected in Wuhan.

The team called for further investigation into the possibility of "cold chain" transmission, referring to the transport and trade of frozen food.

Daszak: "We've done a lot of work in China and if you map that back it starts to point towards the border and we know that there is very little surveillance on the other side in the whole region of South East Asia."

"China is a very big place and South East Asia is a very big place. The supply chains to the Huanan seafood market were extensive, they were coming in from other countries, they were coming in from various parts of China, so to really trace that back it's going to take some work."

"He added that the focus should now be on those supply chains

After visiting the Wuhan Institute of Virology, they have closed the lid on a controversial theory that coronavirus came from a lab leak or was made by scientists.

Another line of investigation is whether the virus could have spread through imported frozen food.

But Dr Embarek said a visit to the laboratory during the mission showed it was "very unlikely" that anything could have leaked out.

He said the laboratory theory was "not in the hypotheses that we will suggest for future studies"."

This smacks of the same stench as the Proximal Origins paper. The point is not to find the origin - just to have scientists lend their weight to closing down speculation of a lab leak.

The frozen food theory is plain silly - but seems that's what they're trying to go with. That way they can argue that it didn't come from China at all.