Evidence is growing that the ban on mobile phones in hospitals is unnecessary and could even in some cases be detrimental to patients.

Reports in The Lancet and the British Medical Journal have urged hospital administrators to end the ban, which was introduced after a Medical Devices Agency report found that four per cent of phones interfered with equipment.

Researchers at St Mary's Hospital in London and the John Radcliffe Hospital in Oxford found that modern Global System for Mobile communications phones give out a fraction of the emissions of earlier models.

The negligible risk the phones pose to equipment is outweighed by their usefulness in stopping patients feeling so isolated, the researchers argued.

"Many patients suffer significant isolation while in hospital and are unable to contact their relatives or businesses to inform them about their condition, or when they may be discharged," the research said.

"The provision of phones for patients and relatives on wards is often inadequate and goes only some way towards addressing the needs of patients."

Mobile phones can affect the way pacemakers work, by speeding up or slowing down the heart pump. However, this is only a danger at a distance of 10cm or less, and people fitted with the devices are allowed to use mobile phones as long as they use them on the opposite side to the pacemaker and do not carry them in their breast pockets.

One hospital, the Chelsea and Westminster in London, does allow mobile phone use in certain sections of its wards, and has reported no problems with their use.