England's exams watchdog says the way a tiny wireless "spy" earpiece is being marketed to students is "disgraceful".
The basic model is "especially designed for high school"
The Qualifications and Curriculum Authority said it had been alerted to the Examear device by a teacher outraged by the advertising.
A spokeswoman for the authority said it would take whatever action it could against the Canadian company involved.
She said students could be barred from all qualifications if caught cheating in one of their assessments.
The Examear website is headed: "Helping students succeed. Worldwide!"
It says its "tiny and invisible" wireless earphones are also suitable for people such as TV reporters, bar staff and TV game show contestants.
But it highlights the claimed advantages to students.
"No more breaking your head over a difficult tests or exam.
"No more memorising long and boring speeches.
"No more thinking about getting caught by using old notes - paper techniques."
The QCA said it was not obvious how someone taking an exam would communicate the questions to an accomplice who might transmit the answers.
But an earpiece could be used to receive information from an MP3 player as well as via mobile phone.
A spokeswoman said the QCA would be warning exam invigilators to be aware of the devices - while conceding they would be very hard to spot.
Its director of regulation and standards, Isabel Nisbet, said: "The advertising of this product is absolutely disgraceful.
"As a regulator we take malpractice very seriously and will be taking any action we can."
Examear was not immediately available to comment.
Last year the QCA published a report it had commissioned from cheating expert Prof Jean Underwood of Nottingham Trent University, which concluded that the increase in available technology has made it easier to cheat.
Prof Underwood said technological solutions such as jamming mobile phones should be investigated.