Jet hand dryers spread dangerous bacteria around bathrooms and are significantly less hygienic than traditional paper towels, scientists have found.

An international study in hospitals established that modern dryers create an aerosol effect, blasting E. Coli as well as traces of faeces and the bacteria responsible for septicaemia onto surfaces.

While the devices can often be activated without being touched, which is supposed to improve hygiene, they are problematic because people fail to properly wash their hands, the experts said.

This leaves harmful bacteria on the surface of the skin ready to be blown around the room.

By contrast, paper towels absorb the bugs better, preventing other people from becoming exposed to them.

Published in the Journal of Hospital Infection, the study, the largest of its kind, was partly carried out at Leeds General Infirmary.

Department of Health guidance says air dryers should only be placed in public rather than clinical areas of the hospital, but only because of concerns around the noise.

The study authors wrote the rules on the use of jet dryers need to be strengthened on the in the light of the new evidence.

"The problem starts because some people do not wash their hands properly,” said Professor Mark Wilcox, who led the study at the University of Leeds.