Mobile phones can harbour 18 times more living bacteria than a flush handle on a men’s toilet, according to research for consumer group Which?

A hygiene expert who swabbed and analysed 30 handsets for the study found seven had warning or high levels of environmental bacteria.

One harboured levels of bacteria, including faecal coliforms, high enough to give its user a serious stomach upset.

Which? said the findings suggest millions of UK mobiles would exceed the recommended acceptable levels of bacteria.

While not immediately harmful, elevated levels indicate poor hygiene and can act as a breeding ground for more serious bacteria.