A study by a consumer group has discovered shockingly large amounts of dirt and harmful bacteria on the humble office keyboard, with one in the study containing five times more bacteria than a toilet seat... Or 150 times the safe limit of bacteria’s such as E.coli and staphylococcus aureus.

The germs found could cause various forms of illness, including food poisoning type symptoms. The main culprits for growing bacteria on a keyboard are people who eat lunch at their desks, and let the crumbs fall between the keys; and those who do not wash their hands properly.

The study, by consumer group Which? found that 10-percent of people said they never cleaned their keyboard, with a further 20-percent admitting to never cleaning their mouse, and almost half cleaned their keyboard less than once a month.

Which? Computing editor Sarah Kidner said: "Most people don’t give much thought to the grime that builds up on their PC but if you don’t clean your computer you might as well eat your lunch off the toilet."

"Why not give your PC a spring clean? It’s quite simple to do and could prevent your computer from becoming a health hazard."