Prosecutors have decided not to press charges against four military instructors investigated over the leak of sensitive defense data, officials said Jan. 11.

The decision means one officer has been indicted for allegedly leaking information in 2002 in violation of a Japan-U.S. security pact.

In December, police asked prosecutors to take over the investigation of the four naval academy instructors and their alleged roles in leaking to students classified data involving U.S.-developed technology for Aegis radar systems. The technology is used on several Japanese and U.S. warships that carry missile interceptors.