American scientists are working their Chinese counterparts to investigate the origins of the novel coronavirus, a prime demand of US President Donald Trump and several other countries, an official media report here said on Wednesday.

While there is no official announcement here, the state-run CGTN television reported on Wednesday that the China Centre for Disease Control and Prevention is facilitating the cooperation between Dr. Ian Lipikin, Director for Centre for Infection and Immunity of Columbia University, and Prof Lu Jinhai of Sun-Yat-Sen University of Guangzhou to conduct the probe.

“The two are working together to determine whether the virus emerged elsewhere in China before Wuhan in December” last year, the report said. It is also not yet clear whether the investigation has the official consent of the US government.

The report about the probe came as China is fighting back mounting calls for an international enquiry into the source of coronavirus which broke out in Wuhan and spread to the whole world.

China on Monday said such a probe has no precedence or legal basis besides investigations into such pandemics in the past had not provided any conclusive results.

Besides Trump, who stepped up demand for an investigation into the origins of the novel coronavirus and whether it escaped from Wuhan Institute of Virology, Britain, Australia and Germany called for more transparency from Beijing on COVID-19 origins.

Chinese Foreign Ministry spokesman Geng Shuang on Monday played down the calls for enquiry saying that the investigations in the past on such viruses achieved little.