Kyushu Electric Power Co. Reports Missing External Drive Containing Data for Over 10 Million Customers in Japan

FUKUOKA, June 12 — Kyushu Electric Power Co., Inc. confirmed Friday that an external storage drive containing private data belonging to more than 10 million customers is missing from a server room cabinet at one of its facilities in the Fukuoka Prefecture.

The utility company stated that the device was discovered unaccounted for during routine checks after being left unlocked inside a secure area. The incident occurred on Thursday evening, prompting an immediate internal investigation and notification to relevant authorities under Japan’s Personal Information Protection Act.

Kyushu Electric Power Co., Inc. has not yet recovered the drive or determined how it went missing from the cabinet. Company officials described the data as including customer names, addresses, account numbers, and usage history — information that could be used for identity theft if compromised in unauthorized hands.

The utility operates across seven prefectures in southern Japan, serving millions of households and businesses with electricity services. It is one of several regional power providers under pressure to strengthen cybersecurity protocols following a series of high-profile data breaches affecting Japanese corporations over the past year.

In response to the incident, Kyushu Electric Power Co., Inc. has launched an internal review of its physical security procedures at all major facilities and engaged third-party forensic experts to assist in tracing the missing device. The company also established a dedicated hotline for affected customers seeking guidance on monitoring their personal information.

Japanese regulators have not yet issued formal penalties or public statements regarding the incident, but officials from the Personal Information Protection Commission are expected to oversee compliance with disclosure requirements and assess whether additional measures were taken promptly after discovery of the missing drive.

No evidence has been found linking the disappearance to external actors or organized criminal groups. However, investigators have not ruled out insider involvement or accidental removal by authorized personnel who may have failed to secure the cabinet properly before leaving the premises.

The utility company declined to comment on whether any unauthorized access attempts were detected following the loss of the drive. It also did not specify when it expects to conclude its investigation or provide a timeline for potential data breach notifications beyond initial customer advisories already issued.

As inquiries continue, Kyushu Electric Power Co., Inc. faces growing scrutiny over how sensitive consumer information was left accessible within an unlocked cabinet in what should have been a restricted environment. The situation remains fluid as authorities and company representatives work to locate the drive or determine whether its contents were accessed without authorization.