A South Korean man who gained “millions” after reproducing 5,000-won bills over a period of more than eight years has been caught by police.

Kim, identified only by his surname, used some 250 million won ($215,000) “worth” of counterfeit money since March 2005, which he reproduced from a single 5,000 won note, according to police.

The counterfeit money was skillfully reproduced, making it hard for people on the street to pinpoint the fake bills from the real ones, Yonhap reports.

A shopkeeper reported the suspicious bill to police, which led to Kim’s arrest early this month.

The Bank of Korea said Tuesday it was giving a reward to the shopkeeper and police officers who caught Kim, reports Wall Street Journal.

The latest central bank data show there were 2.2 fake banknotes per million in circulation as of the end of 2012. The number of counterfeit 5,000 won notes declined 20% from last year.

“Counterfeiting attempts are declining here after we strengthened anti-forgery features such as color-shifting ink and holograms on banknotes,” said an official at the BOK’s currency issuance department.