Mobile phone firms have been accused of concealing warnings about the health risks of using their handsets.

A warning that Apple’s popular iPhone should be kept at least 15mm away from the body is buried deep inside the manual.

BlackBerry goes even further, saying customers should use their devices hands-free or keep them an inch from the body ‘including the abdomen of pregnant women and the lower abdomen of teenagers’. Again, this advice is hidden in the instruction booklet.

All other manufacturers, including Nokia and HTC, carry similar small-print warnings despite insisting that holding mobiles against the ear and head is harmless.

Health campaigners and politicians on both sides of the Atlantic are calling for clear warnings to be put on handset boxes.