Professor Ville Vuorinen of Aalto University in Finland told the BBC: “If you go there, only go there seldom as possible. Stay there as short a time as possible”

In a statement accompanying the video, the researchers said: “Preliminary results indicate that aerosol particles carrying the virus can remain in the air longer than was originally thought, so it is important to avoid busy public indoor spaces.

“This also reduces the risk of droplet infection, which remains the main path of transmission for coronavirus.”