The use of U.S. money transfer companies to send swindled funds to Russia and Ukraine has spiked, involving dozens of apparently unsuspecting people hired to unwittingly commit Internet banking fraud, police sources said.

Unable to track the money beyond those countries, Japanese law enforcement has asked for help from Russian counterparts through Interpol to determine the recipients, the sources said. Investigators also plan to get help from Ukrainian authorities.

Using stolen IDs and passwords to infect account holders' computers with viruses, perpetrators stole about ¥760 million from Japanese Internet bank accounts in 766 cases this year through Oct. 15, according to a tally by the National Police Agency.