The study looked at data from 2006-09 on viruses that were structurally very similar to the new coronavirus strain.

It found that the 1,663 participants were much less likely to be infected if they washed six times a day.

Hand washing more than 10 times a day however did not seem to cut the risk of infection further.

Coronaviruses are a family of viruses that mostly cause mild illness such as the common cold. All of them, including the one that causes Covid-19, can be killed by soap and water.