Academics at Zagreb University are on the lookout for students using hands-free mobile phone kits to cheat in examinations.
Professors overseeing exams have been asked to keep computers switched on to watch for the telltale screen distortions caused by mobile phone frequencies.
One student, who did not wish to be named, said she had passed five exams using a hands-free phone. "If you have long hair, it's easy to cheat. You simply dial the number before entering the examination and whisper the questions to the person on the other end," she said.
University authorities said they were aware of the situation and had expelled three students this year for using this method to cheat.
But Desa Mlikotin Tomic, vice-dean of the faculty of economics, said it was impossible to monitor everyone. "We cannot search every student who comes into the exam. The only thing we can do is to pay closer attention and impose heavy punishments."