South Korea's military security is in hot water.
Two suspected spies involved in business with North Korea were arrested in early May on charges of collecting military intelligence.
Their roles were to disturb global positioning satellite navigation signals, which affects hundreds of commercial flights and ships in South Korea.
Officials say the spies got information on the GPS-related technology from a South Korean engineer identified by his surname Jeong, who is now in police custody.
The technologies included electronic jamming devices and a radar system for air force defense.
A suspected North Korean agent in Dandong, a Chinese city along the North Korean border, instructed the spies in July last year.
Experts are also assuming other confidential military information was leaked, including data on missile-related antenna.
The antenna is critical to staging a rocket launch.
It confirms the wavelength of signal communications.
The export of the antenna is banned, according to the United Nations Security Council Resolution 1874.
[Interview : Shin In-gyun, President
Korea Defence Network] "If North Korea secures more information on how to control staging missiles, the country will be capable of raising the accuracy of their new long-range rockets. And this will be a serious threat to neighboring countries."
South Korean media reports that information on drone antisubmarine helicopters is suspected to have been leaked, while the country's defense ministry has refused to comment.
Hwang Ji-hye, Arirang News.