A health expert in the US has claimed that many toilets are cleaner than computer workstations.

A study by University of Arizona microbiologist Chuck Gerba demonstrated that the average workstation has 400 times more bacteria than the average loo.

According to Gerba, office lavs had the lowest levels of germs of all of the surfaces he tested, but some of the office workstations he looked at were bacterial nightmares.

The telephone is the worst offender with the highest bacteria counts, closely followed by the desktop itself and the computer keyboard.

Most workstations are hardly ever cleaned, and Gerba said that they can "sustain millions of bacteria that could potentially cause illness".