Beijing - (AFP) - Beijing considered Wednesday that Washington was harming its credibility after the director of the US Federal Bureau of Investigation (FBI) said that his agency believed that the Covid outbreak was "most likely" caused by an accident in a laboratory in Wuhan, China .

FBI Director Christopher Wray told Fox News on Tuesday that his office assesses that the spread of the virus was "most likely the result of a possible laboratory accident in Wuhan."

Chinese officials denied the remarks, calling them a smear campaign against Beijing.

"The United States once again raises the theory of laboratory leakage, which will not tarnish China's reputation but diminish its own credibility," said Foreign Ministry spokeswoman Mao Ning at a regular press conference on Wednesday.

Ray's comments followed a report earlier this week that said the US Department of Energy assessed a leak from a Chinese laboratory as the most likely cause of the Covid outbreak.

The US Department's discretion is important because it works with a network of national laboratories, some of which conduct advanced biological research.
But other US intelligence agencies believe that the virus emerged as a result of natural factors.

In his interview Tuesday, Wray also accused the Chinese government of trying to block US efforts to investigate the origins of the epidemic.

"The Chinese government does everything it can to try to sabotage and disrupt ... the work that our US government and our close foreign partners are doing," the FBI director said.

In response, spokeswoman Mao repeated the longstanding Chinese claim that the virus may have leaked from the US military research laboratory at Fort Detrick, Maryland.

"The United States should respect science and facts, cooperate with the World Health Organization as soon as possible, invite international experts to conduct tracking research in its country, and share research results with the international community," said the Chinese Foreign Ministry spokeswoman.

The scientific community considers it crucial to determine the origin of an epidemic in order to better control or even prevent similar pandemics.