The Chinese virologist whose work has been the subject of controversial theories about the origin of the novel coronavirus has dismissed rumours that she has defected from China. Shi Zhengli, a renowned researcher of bat coronaviruses, wrote on WeChat on Saturday that she and her family had not fled the country, despite coming under heavy scrutiny amid concerns that the virus responsible for the Covid-19 pandemic had originated at the Wuhan Institute of Virology (WIV) in central China where she works. Chinese state newspaper Global Times said it had confirmed the post had been written by Shi. “No matter how difficult things are, there will not be a ‘defector’ situation as the rumours have said,” Shi wrote. “We have not done anything wrong and we continue to have strong faith in science. There must be a day when the clouds part and the sun comes out.” Rumours circulated online claimed Shi and her family had smuggled hundreds of confidential documents out of the country and were seeking refuge at the United States embassy in Paris. The virologist has been the subject of intense speculation over her work at the WIV, which has denied having any links to the coronavirus that began spreading in Wuhan at the end of last year. Shi has worked for years with bat coronaviruses at her lab at the institute, and discovered the natural bat reservoir for the Sars (severe acute respiratory syndrome) pathogen that spread in southern China from 2002 to 2003. Scientists believe the novel coronavirus most likely spread to humans from animals , perhaps a bat, and say it is highly unlikely to have spread because of an accident at the institute, and is even less likely to have been manufactured. However, the exact source of the virus remains unknown, and China has said it is conducting its own investigations into the matter. Bat virus? Bioweapon? What the science says about Covid-19 origins In February, Shi took to WeChat to refute the idea that the virus originated in her lab, saying she guaranteed it “with my life”. Beijing has rejected the characterisation of Covid-19 as originating in China, sparring in particular with the US over its origin. A Chinese foreign ministry spokesman even suggested it had been brought into China by the US military . US President Donald Trump on Thursday said he had a high degree of confidence that the virus was linked to the WIV, even after US intelligence said that while it was “not man-made or genetically modified”, it was still examining information to determine if the outbreak began from infected animals or a lab accident. There have been growing calls for an international investigation into the origin of the virus , including from the US, Australia, and the European Union. The World Health Organisation on Friday said it would take part in an international investigation into “the animal origins” of the virus.