The police have launched a full-scale investigation into Kakao Pay regarding allegations that the company transferred the personal information of approximately 40 million individuals to China's Alipay without customer consent.

According to the Anti-Corruption and Economic Crime Investigation Division of the Gyeonggi Nambu Provincial Police Agency on the 14th, they have been investigating Kakao Pay on charges of violating the Credit Information Act since March, following a request for investigation from the Financial Supervisory Service.

According to the financial authorities, Kakao Pay is suspected of transmitting approximately 54.2 billion instances of personal data belonging to 40 million customers to the Chinese mobile payment service Alipay from 2018 to this past May.

The issue originated during the process where Apple iPhone users registered Kakao Pay as a payment method. It was found that during the process of transmitting payment information to Apple via an Alipay relay, data such as encrypted mobile phone numbers, email addresses, and charge balances were transferred to Alipay. Alipay reportedly utilized this information to build an 'NSF score' calculation model, an indicator used to assess the likelihood of insufficient funds.

The incident has already faced severe sanctions from financial and personal data protection authorities. In January of last year, the Personal Information Protection Commission imposed a 5.968 billion won fine on Kakao Pay. Subsequently, in February, the Financial Supervisory Service also handed down heavy disciplinary actions, including an institutional warning, a 12.976 billion won fine, and a 4.8 million won penalty.

Based on the relevant materials received earlier from the Financial Supervisory Service, the police plan to verify the specific facts of the case and carefully review the future direction of the investigation.