Prof Leung told The Guardian during a visit to London that the priority now is to establish the size and shape of the ‘epidemic iceberg’.

Most experts believe that each infected person has gone on to transmit the virus to around 2.5 people, giving an ‘attack rate’ of 60 to 80 per cent.

The death rate, however, is thought to be much lower. Prof Leung expects it to be around one per cent once milder cases, that have not been diagnosed, are taken into account.

‘Is 60 to 80 per cent of the world’s population going to get infected?,’ he asked, ‘Maybe not. Maybe this virus will come in waves.

‘Maybe the virus is going to attenuate its lethality because it certainly doesn’t help it if it kills everybody in its path, because it will get killed as well.’