Japan may raise a vessel that sank in the East China Sea after a firefight with Japanese Coast Guard cutters. The mystery ship will not be salvaged immediately.

Japanese officials say they want to raise the sunken ship to determine its origin. They say the existing evidence indicates it came from North Korea.

Japan's military lacks the equipment for the salvage operation. The Defense Agency says a private company likely will be hired for the mission, which could take some time to do.

The vessel, after being chased by Japanese Coast Guard cutters Saturday and Sunday, sank in waters that are in China's exclusive economic zone. That means Tokyo needs Beijing's consent to raise the boat.

Japanese officials say salvaging the vessel would give them valuable information about the sophistication of North Korea's surveillance technology. The Stalinist state is one of the world's poorest nations, but is believed to have advanced military capabilities.

Two bodies have been recovered from the site of the sinking, and items in their clothing and a life jacket bore Korean writing. About 15 crew members were believed to have been on board. Japan media say the government has another piece of evidence tying the boat to Pyongyang, intercepted radio transmissions. Japanese broadcaster NHK and the Sankei newspaper reported Wednesday that a Japanese monitoring station recorded radio messages between North Korea and the mystery ship. Chief Cabinet Secretary Yasuo Fukuda offered scant information about the radio intercept when he spoke with reporters Wednesday.

Mr. Fukuda says he will not give out any details of the communication because that might hamper intelligence gathering in the future.

Some media reports say that the Japanese were tipped off about the radio signals by the United States military after a U.S. spy satellite spotted the vessel near Japan's Amami island on December 18.

The media reports quote Japanese officials as saying a radio exchange between the ship and a shore station were on a frequency used by the North Korean ruling Worker's Party.

North Korea, so far, has made no mention of the incident. There are no diplomatic relations between North Korea and Japan.