At that time, it was reported that the novel coronavirus emerged in Wuhan, China, and spread throughout the world, causing a pandemic. 

Data from several countries claimed the virus was circulating months earlier than previously thought, suggesting that China covered up early spread before informing the world.

Following a conducted research by WHO scientists, Peter Embarek, the leader of the team, said on Tuesday at a press conference held in Wuhan, that studies of infection and mortality data, blood samples, and other hospital records had failed to uncover any evidence of significant transmission before December 'in Wuhan or elsewhere'.

Dr. Embarek reported the findings of a month-long fact-finding mission in China.

During the one month of research, the experts reportedly spent two weeks in quarantine, and the same again on fieldwork. They also spent just an hour at the seafood market where many of the first reported clusters of infections emerged over a year ago.

The teams also appeared to spend several days inside their hotel, receiving visits from various Chinese officials without going out into the city.

But deeper research was carried out at the Wuhan virology institute where they spent nearly four hours and said they met with Chinese scientists there including Shi Zhengli, one of China's leading experts on bat coronaviruses and deputy director of the Wuhan la

Opening the press conference, Dr. Liang Winnian, the head of China's Wuhan research team, said that while transmissions from animals to humans via bats remain the likeliest origin of Covid, the original host 'has not been identified'. 

He added that studies showed the virus 'can be carried long-distance on cold chain products,' appearing to nudge towards the possible importation of the virus - a theory that has abounded in China in recent months.

He also said there was 'no indication' the sickness was in circulation in Wuhan before December 2019 when the first official cases have been recorded.

WHO foreign expert Ben Embarak, who was based in the WHO's Beijing office for two years from 2009, backed up the assertion saying there was no evidence of 'large outbreaks in Wuhan' before then.

Before the mission began, it was trailed by fears of a whitewash, with the US demanding a 'robust' probe but China fired back with a warning not to 'politicise' the investigation.