Such high levels of bacteria was found from one of the sample mobile that could have given its owner a serious stomach problem.
"The levels of potentially harmful bacteria on one mobile were off the scale. That phone needs sterilising," said Hygiene expert Jim Francis after carrying out the test.
Enterobacteria, a group of bacteria that live in the lower intestines of humans and animals and include bugs such as salmonella, had been found from some of the sample mobiles.
"What this shows is how easy it is to come into contact with bacteria. People see toilet flushes as being something dirty to touch but they have less bacteria than phones," added Francis.
The test had showed how people should be more cautious over usages of mobile phones.
The magazine said, "people need to be mindful of that by observing good hygiene themselves and among others who they pass the phone to."
The magazine 'Which?' had previously found that some computer keyboards carry more harmful bacteria than a lavatory seat.