NANCHANG -- A college student was detained Sunday night in Jiangxi province, East China, for posing as a high school student and sitting the "Gaokao" (college admission exam), local police announced on Monday.

The suspect, Peng, 20, is a student in Wuhan city, central China. He confessed to the police and gave the names of five other substitute exam sitters.

According to Peng, he and his fellow substitutes were managed by Zhao, 48, who hails from Shandong Province, east China. Zhao arranged accommodation for Peng and the other five substitutes and supplied them with exam attendance cards.

The scam was exposed by a reporter who had gone undercover as an exam substitute. One suspect was apprehended in an exam room on Sunday morning, less than half an hour before the first test was due to end.

The Ministry of Education said in a statement Monday that an investigation has been launched into the cheating racket and should those implicated be found guilty of wrongdoing they will face serious punishments.

Regulations in Guangdong and Shandong mandate that college students could face expulsion if they are found to have sat the Gaokao for high school students.

Over 9.4 million high school students took the Gaokao on Sunday and Monday, and the ministry said this year's exam had gone smoothly as of Monday and had not been tainted by any huge cheating scandals.

Public security authorities across the country have clamped down on the distribution of wireless devices used for cheating, the sale of cheat sheets, and the practice of substitute exam sitters in the run up to the exam, according to the ministry.

Law enforcers had apprehended 23 suspects nationwide before the start of the Gaokao.