A Korean man has been under investigation on charges of stealing military secrets after being employed by a company developing and managing computer programs for the government, prosecutors said Monday.

The 43-year-old man was previously convicted of violating the National Security Law banning pro-North Korea activities.

But it is unclear whether the man, identified only by the initial K of his surname, handed over the acquired information to the North, according to the investigators.

"Police caught the man earlier this year on charges of stealing military secrets and sought an arrest warrant, but the court rejected it, saying he was unlikely to run away or destroy evidence," said Park Kyung-ho, a senior prosecutor at the Suwon District Prosecutors' Office. "We summoned him once for questioning without detention, but he used the right of silence."

According to the prosecutors, K was employed by the unidentified subcontractor in charge of developing and managing computer programs for the government in March 2005. He took part in the Joint Chiefs of Staff (JCS)'s project to develop a system for sending real-time information on battlefield situations to military command centers the same year, they said.

He is suspected of leaking a large amount of confidential military information during the past six years before he was suspended from the job in March last year.

Among the information allegedly leaked was the JSC's written proposal for the new system and node IP addresses of key computers being used by the military.

According to prosecutors, K was hired by the company although he was sentenced to one year in prison, suspended for two years, in 2002 for posting pro-Pyongyang material on the Internet.

The suspect has entered the JCS's computer network center several times and visited North Korea in 2007 and 2008, prosecutors said.

He also had file folders named the JCS, the Financial Supervisory Service and the Supreme Prosecutors' Office in his computer, which was confiscated by the investigators, an indication that he stored the leaked information for possible transmission.

They noted that the man was found to have sent e-mails to officials of the North Korean Web site "Ryomyong" but there is no compelling evidence that the stolen information was sent to the North. (Yonhap News)