A total of 25 students in Central China's Henan province were found to be substitute examinees during the National College Entrance Exam last week, said the provincial education bureau.

The substitute examinees have violated the rules and regulations and will be punished according to the law, the provincial education bureau said in a statement on Sunday.

Apart from the substitute examinees, the education authority also found another 31 students cheating in the exam and 24 students taking communication tools to the test rooms, according to the statement.

More than 805,800 students in Henan province participated in the two-day exam on June 7 and 8, said the statement.

A news report carried by the Southern Weekly said that finding substitute examinees has become "a hidden industry" in Henan province — the organizers seek proper college students as substitutes, bribe the test room supervisors and make a profit of about 20,000 yuan from each customer.

A substitute gets only 10,000 yuan as a reward on average, said the report, which was published on June 7, the first day of the exam.

The education authority has tightened the discipline of test rooms during the whole process, said the provincial education bureau's statement.