Seoul:E-commerce giant Coupang Corp. has initiated legal proceedings to contest a 620 billion won (US$462 million) fine imposed by a state-run data protection agency due to a significant data breach, according to sources.

According to Yonhap News Agency, Coupang has filed two lawsuits with the Seoul Administrative Court to overturn the penalties levied by the Personal Information Protection Commission in June. The commission had fined Coupang a record 624.7 billion won for privacy infringements, including the unauthorized access to personal data of over 37 million users.

The fine comprises 423.6 billion won for the data breach, with an additional 201.1 billion-won penalty for unauthorized data collection and other infractions. This represents the largest fine ever imposed by the commission on a single entity.

The punitive action followed Coupang's delayed disclosure of a massive data leak in November, which compromised the personal details of users in South Korea, such as names, phone numbers, and delivery addresses. An investigation concluded that a hacker accessed information from approximately 37.5 million users, including 33.2 million Coupang members and 4.3 million others.

Under the personal information protection law, companies can be fined up to 3 percent of their annual sales for data breaches, excluding sales from unrelated business activities. Coupang has reported average annual sales of about 36 trillion won over the past three years.

The data breach has also sparked tensions between Seoul and Washington, as some U.S. officials and lawmakers have expressed concerns about the treatment of the Korean unit of the U.S.-listed Coupang Inc. during the investigation.