The Defense Agency opened an investigation Tuesday into a suspected case of blackmail involving data allegedly leaked through a subcontractor hired to help develop a 1.1 billion yen computer network for the Self-Defense Forces.
The data, which includes plans of the system's design and more than 10,000 Internet Protocol addresses on the network used by the Ground Self-Defense Force and the Air Self-Defense Force, is believed to have been taken from a software firm subcontracted by Fujitsu Ltd., the developer of the system.
In late June, three to four men contacted Fujitsu on several occasions to blackmail the company into buying back the data, the officials said. They did not specify a price. According to sources close to the case, one of the suspected blackmailers may be a former Self-Defense Force member who had belonged to a unit in western Japan. On one occasion, one of them claimed to be a "newphew" of a former Defense Agency chief, they said.