Police have arrested at least 64 people suspected of selling hi-tech devices to help students cheat in China's annual make-or-break national college entrance exam to be held June 7-8, authorities said Sunday.

Police arrested suspects from six crime groups, including 58 people in southeastern Fujian Province, over the past few days. A number of devices, such as wireless earphones, signal emitters, scanner-imbedded pens and watches, were confiscated, Lin Qitian, a provincial official in charge of college enrolment, told reporters.

Lin said police acted after mobile phone messages selling cheating devices or alleged exam contents were transmitted to students. These scam messages were sent out from eight mobile phone numbers controlled by crime groups.

Suspects arrested in Longyan city told police they had earned 7,900 yuan (1,158 U.S. dollars) from ten students selling these devices, Lin added.

Meanwhile, in northwest China's Gansu Province police arrested other six people suspected of selling espionage-type devices to students for cheating in the exam.

The suspects had collected 28,600 yuan (4,194 U.S. dollars) as down-payments from 11 students, a police official in Huachi county said. These cheating devices were sold for 20,000 to 30,000 yuan per unit, he added.

Police are investigating these cases.

To many Chinese students and their parents, the annual college entrance exam, known as "gaokao", is considered the most important exam in their lives. Although higher education has become much more accessible to ordinary Chinese in the past decade, gaokao continues to play a critical role as the country's largest and best-trusted mechanism to offer China's most talented students the opportunity for university education.

More than 9.57 million high school students will sit for this year's exam, the education authorities said, and about 6.57 million will later be accepted at the nation's universities.