The BBC’s China correspondent, John Sudworth, travels to Wuhan – the city on the banks of the Yangtze river where Covid-19 first emerged. As the city returns to life, he examines one of the biggest questions on everyone’s mind: did the virus emerge naturally or could it have been leaked, as the US alleges, from a Wuhan lab, where work was being carried out to research bat viruses? As John and his team discover, asking questions and getting answers in Wuhan is no easy task. Reporter: John Sudworth Producer: Kathy Long Photo: Two motorcyclists in Wuhan, China - June 2020 Credit: Getty Images