A former Air Self-Defense Force officer was arrested Friday on suspicion of leaking top secret information seven years ago about a U.S.-made E-2D airborne early warning plane.
So Kanno, a 58-year-old former colonel who left the ASDF in 2017, is alleged to have used a personal computer to show data on its capabilities to a trading company employee who was not authorized to access the information.
The leak allegedly occurred at Iruma Air Base in Saitama Prefecture around Jan. 9, 2013, the police said.
The former colonel is also suspected to have given the employee a USB memory device containing the data, which was designated as a special defense secret under a 1954 law based on the Japan-U.S. Mutual Defense Assistance Agreement.
He has denied the allegation, according to investigators.
It is only the third alleged violation of the 1954 law to be investigated by the police.
Following his arrest, Defense Minister Taro Kono told reporters that whether the top secret information on the E-2D was leaked to a third country or not has not been confirmed.
Kono said he regretted the arrest, figuring the leak "could damage public confidence and the trusting relationship between Japan and the United States."
Kanno was chief of the planning division in the research and development department of the ASDF's Air Development and Test Command Headquarters at the time, according to the police.
The U.S. government entrusted Kanno with the confidential information around 2010, the police said. The trading firm employee passed the USB device on to an employee of a U.S. aircraft-maker that was a rival of the company that made the plane, sometime around July 2013.
The rival later notified the U.S. government of the alleged leak, according to the police.
