London, Dec. 5: Students should sit exams in metal-lined rooms to block mobile phone signals amid fears that technology is fuelling a “substantial” increase in cheating, a government-backed study said yesterday.

Thousands of children may be using phones to send text messages to friends for answers or to access the Internet during tests.

Others down-load data on to MP3 players smuggled into exam halls.

The report, commissioned by the Qualifications and Curriculum Agency, the official exams watchdog, said staff must take drastic action to stop sophisticated cheats undermining the examinations system altogether.

In one recommendation, teachers are asked to consider using a Faraday cage, named after its inventor, Michael Faraday, in which metal is built into the walls of rooms to block electromagnetic waves.

Airport-style security scanners should also be installed to stop candidates taking in phones and other aides.

Prof. Jean Underwood, from Nottingham Trent University, who carried out the study, suggested that large universities should fingerprint students to stop friends taking exams for them. “Digital technologies have brought equity to cheating,” she said. “Access is no longer for the knowing few but is there for the majority.”

Cheating in exams has soared. The QCA said that more than 4,500 candidates were penalised in 2005, an increase of 27 per cent in 12 months. Of these, about 1,100 smuggled in mobile phones.