Claims that the coronavirus pandemic originated in a laboratory in the Chinese city of Wuhan have no basis in fact, the head of the lab said, adding that there were still no conclusive answers as to where the disease started.
Conspiracy theorists have claimed SARS-CoV-2, now responsible for more than 200,000 deaths worldwide, was synthesised by the Wuhan Institute of Virology (WIV), based in the city where the disease was first identified.
Though the scientific consensus is that the coronavirus evolved naturally, such claims have gained traction.
The US President, Mr. Donald Trump, said on April 15 that his government was investigating whether it had originated in the Wuhan lab.
Prof. Yuan Zhiming, professor at WIV and the director of its National Biosafety Laboratory, said 'malicious' claims about the lab had been 'pulled out of thin air' and contradicted all available evidence.
'The WIV does not have the intention and the ability to design and construct a new coronavirus,' he said in written responses to questions. 'Moreover, there is no information within the SARS-CoV-2 genome indicating it was manmade.'
Some conspiracy theories were fuelled by a widely read scientific paper from the Indian Institute of Technology, since withdrawn, claiming that proteins in the coronavirus shared an 'uncanny similarity' with those of HIV. However, most scientists now say SARS-CoV-2 originated in wildlife, with bats and pangolins identified as possible host species.
'More than 70 per cent of emerging infectious diseases originated from animals, especially wild animals,' Prof. Yuan said.
'In recent years, we have seen increasing risks posed by close contact between humans and wild animals, with global climate change and the continuous expansion of human activities,' he said.
All seven known human coronaviruses have origins in bats, mice or domestic animals, scientists say.