Beijing has hit back at the United States for once again stirring up the lab leak theory on the coronavirus pandemic , calling on it to stop “smearing China” and “politicising the origins of Covid”. It followed American media reports , citing classified intelligence provided to Washington, that said the US Department of Energy had concluded that a Chinese laboratory leak was the most likely cause of the pandemic. The Chinese foreign ministry slammed the reports on Monday, saying tracing the origin of the coronavirus was a scientific issue that should not be politicised. “Relevant parties should stop stirring up the theory of laboratory leaks, stop smearing China, and stop politicising the origins of Covid,” ministry spokeswoman Mao Ning said. According to a Wall Street Journal report on Sunday, the department was previously undecided on how the Covid-19 virus emerged, and the shift highlighted the divide between US spy agencies on the pandemic’s origin. It noted the department had made its judgment with “low confidence”, citing sources who had read the classified report “provided to the White House and key members of Congress”. Both the Journal and The New York Times said the report was based on “new intelligence”, while the Times cited officials as saying the intelligence was relatively weak and the “low confidence” note suggested its level of certainty was not high. Asked to comment on the issue, Mao said: “That lab leaks are extremely unlikely is an authoritative scientific conclusion, made by Chinese and WHO experts after visiting laboratories in Wuhan and conducting in-depth exchanges with relevant researchers.” Mao was referring to the central Chinese city where the first Covid-19 cases were reported in December 2019. China had always actively supported and participated in global scientific efforts to track the origins of Covid-19, Mao added. Xi warns Chinese labs handling deadly pathogens will face closer scrutiny This comes two weeks after science journal Nature reported that the World Health Organization (WHO) had stopped its investigation into the origins of the pandemic because of challenges in conducting studies in China. However, the WHO has rejected that claim, with director general Tedros Adhanom Ghebreyesus pledging it will “continue to push” for answers. The US Department of Energy oversees American national energy and nuclear developments, and has a network of national laboratories, some of which conduct biological research. Previously undecided, it is the second US agency to now conclude that the pandemic was caused by a lab leak. WHO says Covid-19 origins unclear but lab leak theory needs study In 2021, the Federal Bureau of Investigation concluded with “moderate confidence” that the pandemic was likely to have resulted from a lab leak. The Journal report said “four other agencies, along with a national intelligence panel, still judge that it was likely the result of a natural transmission, and two are undecided”. China has always hit back at any suggestion that the Covid-19 virus originated in one of its laboratories, calling such reports “ politically motivated ”. In October 2021, a report from the US Director of National Intelligence left open the possibility of a “ laboratory-associated incident ”, alongside natural animal-to-human transmission. It also chided the Chinese government for impeding further investigation and said the virology lab near the first known outbreak of Covid-19 in the city of Wuhan lacked adequate biosafety precautions. New Covid origins studies point to Wuhan market, not Chinese lab leak In response, China’s embassy in Washington said the report was “not scientific at all”, and questioned the US government’s use of an “intelligence apparatus instead of scientists” to arrive at an assessment. “The use of intelligence agencies to trace the origins is in itself ironclad proof of politicisation,” the Chinese foreign ministry said.