The origin of the novel coronavirus outbreak remains a mystery, with experts disagreeing on whether the virus came from either a laboratory or a wet market in the city of Wuhan, China.
The lab argument
An aerial view shows the P4 laboratory at the Wuhan Institute of Virology in Wuhan in China's central Hubei province on April 17, 2020. (AFP)
The wet market argument
A Chinese vendor handling chickens at a poultry market in Wuhan, central China's Hubei province. (File photo: AP)
Chinese President Xi Jinping talks by video with patients and medical workers at the Huoshenshan Hospital in Wuhan in central China's Hubei Province on March 10, 2020. (AP)