The Self-Defense Forces' investigation of an SDF member in connection with a news report of an accident in a Chinese Navy submarine in 2005 raises concerns regarding people's right to know and the freedom of the press. It could lead to limits on basic rights and freedoms guaranteed by the Constitution. The investigative unit, equivalent to the military police, suspects that SDF classified information was accessed by a Yomiuri Shimbun reporter. The unit raided the home and office desk of an Air Self-Defense Force colonel suspected of having leaked the information to the reporter.
The article in question appeared on the front page of the Yomiuri on May 31, 2005, under the headline "A fire in a Chinese submarine?" It quoted Japanese and U.S. defense sources as confirming that an accident, believed to be a fire, occurred in the Chinese submarine several days earlier while it was submerged in international waters in the South China Sea between Taiwan and Hainan Island and that the submarine was being towed toward the Chinese island as it was dead in the water.
The article also mentioned that both the Japanese and U.S governments believed that the submarine was conventionally powered, rather than nuclear-powered, and that the accident's impact on the surroundings was negligible. The article identified the submarine as a Ming-class diesel-powered attack submarine.