A client list used by Mitsui Mutual Life Insurance Co. has been leaked, officials of the insurer said Tuesday.

Mitsui Mutual is now investigating the incident, which concerns personal data — such as names, addresses and birthdays — on 74 customers. Most of these clients reside in Tokyo’s Setagaya Ward and the city of Chofu, western Tokyo, the officials said.

The list was compiled in January 2000 and bears the name of a salesperson who later quit the company, the officials said, adding that they were informed that the person had shredded the list upon quitting.

Mitsui Mutual has apologized to all the customers involved and may file charges if it finds evidence of any criminal activity behind the leak, the officials said.

“We will conduct a thorough review of the way customer information is managed to prevent a repeat of such a case,” a spokesman said.

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.