NTT Docomo Inc. failed to notify all its partner banks of suspected deposit theft from bank accounts linked to its e-money payment service last year, it was learned Saturday.
Many unauthorized deposit withdrawals have occurred since last month, mainly at regional banks using relatively simple authentication methods to link their bank accounts to NTT Docomo accounts for the e-money service.
NTT Docomo is in partnership with 35 banks for the service, which allows users to make payments for shopping and send money by registering their bank accounts with the mobile phone giant.
On Thursday, NTT Docomo told a news conference that fraudulent money withdrawals using its payment service had occurred in May last year at accounts at Resona Bank and Saitama Resona Bank, both units of Resona Holdings Inc.
"We did not know (the Resona group cases) until the news conference," a regional bank official said.
"We've checked after the news conference, but we couldn't find any record showing that we received any explanations from NTT Docomo," another regional bank official said.
An NTT Docomo official said that the company did not warn all partner banks about the illicit withdrawals, while some were warned at the working level.
Resona Bank and Saitama Resona Bank suspended new registrations with NTT Docomo for the e-money service last year following the fraudulent money withdrawals.
"At least, we would have investigated how Resona responded if we had received explanations," a regional bank official said, suspecting that NTT Docomo apparently did not want to provide information that may lead banks to reconsider their partnership.