A South Korean businessman has been indicted on charges of handing over classified information to North Korea, prosecutors said Tuesday.

The 55-year-old man, only identified by his surname Kang, is under suspicion of transferring state-of-the-art South Korean military technology between March 2012 and July 2013, as well as providing personal information on hundreds of families separated by the 1950-53 Korean War.

"The (leaked) data were important and could be used by North Korea for military or intelligence operations," said an investigator at the Seoul Central District Prosecutors' Office.

Among the leaked confidential data is the transferring wireless video and audio system technology called "KAISHOT," prosecutors said. The technology was used by the South Korean Navy during the rescue of Korean sailors from Somali pirates near the Gulf of Aden three years ago, they added.

Kang, who is engaged in real estate business with Pyongyang, came into contact with North Korean operatives during his visits to the communist regime in the 1990s.

Prosecutors suspect that Kang made contact with agents belonging to the Reconnaissance General Bureau of the North's Korean People's Army, which oversees espionage operations against the South. (Yonhap News)