South Korean intelligence officials are investigating a local IT company owner suspected of helping a North Korean hacker distribute malignant codes to South Korea, officials said Wednesday.

The National Intelligence Service reportedly raided the home and offices of the South Korean businessman, identified only by his surname Kim, on Tuesday after obtaining a search warrant from a local court.

Kim is suspected of sharing his office computer network with the North Korean hacker through which malicious software was distributed to infect tens of thousands computers in South Korea, officials said.

Up to 100,000 machines are thought to have been infected, which the hacker could have used to steal information and conduct illegal activities, without the owners' knowledge.

Kim, known to be a former activist, may have also passed on a number of South Korean IDs and passwords to the North Korean hacker over the past two years, an act in violation of the national security law, according to officials.

Officials said Kim may have come into contact with North Korean agents several years ago during his stint at an inter-Korean IT venture in China and that they plan to summon him for questioning to verify the facts. (Yonhap News)