The president of a data services firm was arrested Monday in Kawagoe, Saitama Prefecture, for allegedly leaking lists of multiple debtors to loan sharks.
Police say that Kiyoshi Tomiyama, 53, aided and abetted in the provision of illegal high-interest loans.
Tomiyama has admitted that he started collecting lists of debtors from brokers and selling them about 10 years ago, police said.
The investigative team has confirmed that some 75 million yen has been transferred into Tomiyama's bank account and that he was in possession of floppy disks containing the names of about 1.5 million multiple debt-holders, police said.
He is suspected of selling lists of names of a combined 60,000 people for a total of 600,000 yen on six occasions to two senior underworld members between February and June 2002. The two gangsters have been charged with violating the investment law.
Police said they believe Tomiyama leaked similar lists to between 40 and 50 shady lenders affiliated with the Yamaguchi-gumi organized crime syndicate.