• Kyodo News


Information on sea-based surface-to-air missiles was leaked along with data on the Aegis defense system, jeopardizing the deployment of a key defense system, according to sources familiar with the probe by Kanagawa prefectural and Maritime Self-Defense Force police.

MSDF Aegis ships were scheduled to start receiving the state-of-the-art SM-3 interceptor weapons system developed by the United States this year.

The U.S. has lodged a stern protest with the MSDF over its lax management of intelligence.

Commenting at a news conference Tuesday on the SM-3 data leak, Defense Minister Fumio Kyuma said, “I’ve heard nothing about it (the allegation) including whether it is valid or not.”

The case came to light in March after police found that a petty officer 2nd class had stored material containing secret Aegis data, such as an educational program, on computer hard disks discovered at his home in Yokosuka, Kanagawa Prefecture.

He told police he obtained the data from a petty officer 3rd class, though neither was authorized to access the highly classified information. Police investigated further, questioning related officers and MSDF members. The two petty officers are crew members of destroyers belonging to the 1st Escort Flotilla based in Yokosuka.

Police also found that materials on the Link 16 data exchange system — the latest system used in key U.S. warships and fighter jets — have been leaked.

Link 16, which has several times more capacity and is more resistant to electronic jamming than Link 11, is being used for information sharing between U.S. and Japanese military units. It is considered an essential tool in missile defense, which requires a swift exchange of information via reconnaissance satellites.

Materials on both the SM-3 and Link 16 are in the special category of classified information under the 1954 Law Concerning the Protection of Secrets for the Japan-U.S. Mutual Defense Assistance Agreement.

Police have so far interviewed 300 people who compiled the leaked data or are believed to have provided classified information to the petty officer 2nd class.

Police confirmed the latest cases of information leak based on analyses of voluntarily submitted materials, such as personal computers.

On Saturday, police searched an MSDF training school, the First Service School in Etajima, Hiroshima Prefecture, where the leak is believed to have occurred.

Prior investigations have confirmed that information regarding the function of high-performance radar of the previous-generation Aegis system was leaked along with information regarding an antiaircraft system.

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