Japan＊s nuclear regulator has reported the loss of a work-issued smartphone containing highly sensitive contact information after an employee misplaced the device while traveling in China late last year.

The Nuclear Regulation Authority (NRA) said an employee lost the smartphone during a personal trip to China in November, according to reports by the Asahi Shimbun. The device, which has not been recovered, contained the names and contact details of staff in charge of nuclear security 〞 information that is not publicly disclosed due to its high level of confidentiality.

The agency has notified the Personal Information Protection Commission, saying it cannot rule out the possibility of an information leak, although no misuse has been confirmed.

According to the authority and other sources, the employee believes the phone was lost on Nov. 3 while passing through security at an airport in Shanghai. The loss was noticed three days later, after which the employee contacted airport officials and other relevant authorities.

The affected department is responsible for safeguarding nuclear materials at domestic facilities, including measures to prevent terrorism and theft. As a rule, the identities and direct contact details of personnel involved in nuclear security are kept confidential to minimize security risks.

To ensure a rapid response to emergencies such as nuclear accidents or major earthquakes, certain NRA staff are issued disaster-prevention smartphones and are required to carry them at all times.

In response to the incident, however, the agency has warned employees against taking such work-issued smartphones overseas. An official at the authority told Kyodo News that the agency would reinforce guidance to staff and review internal rules, including clarifying policies on carrying government devices during foreign travel.