'Olympic variant' could lead to world tragedy, warns Japanese doctor

Head of the Japan Doctors Union, Dr Naoto Ueyama, says the games could see the emergence of a new COVID-19 strain

A leading Japanese doctor has warned that holding the Olympic Games in Tokyo, with tens of thousands of people from around the world, could lead to the emergence of an "Olympic" coronavirus strain. 

Dr Naoto Ueyama, head of the Japan Doctors Union, says that the arrival of people from 200 nations and territories for the games, due to begin in eight weeks, could open the door for a new strain.

"All of the different mutant strains of the virus which exist in different places will be