Police received a record 377,513 reports of "dubious financial transactions," such as money laundering, from financial institutions in 2014, the National Police Agency said Thursday.
The figure rose 8.1 percent from the previous year and police identified 1,001 criminal cases from the reports, up 4.1 percent, according to the NPA.
Of the criminal cases, fraud such as online auction abuses and fraudulent receipts of welfare benefits accounted for 82.7 percent of the total.
To detect cross-border money laundering, the NPA is exchanging information with overseas authorities on dubious financial deals through its financial intelligence unit, which was set up in April 2007.
Last year, Japan enacted a revised law aimed at reinforcing measures against money laundering.