Tran Huy Quoc, 28, is now being investigated for making usurious loans to 18 students in Ea Kar District, police said Wednesday.
According to an investigation, since September last year until now, Quoc has lent 18 students more than VND300 million (US$12,260) with interest rates of 365-547% per year.
Each borrower must pay him an interest of VND10,000-15,000 every day of the year.
So far, Quoc has pocketed more than VND40 million.
He told the police that it was easier to deal with students because they were afraid of their parents and teachers and all he needed to do was to threaten them that he would tell adults how they had borrowed money from him.
He also made the students sign contracts in which he wrote false interest rates, which were much lower than what he charged in reality.