Lawmaker Lee Eun-jae said the National Intelligence Service officials told lawmakers in a closed-door briefing that Jo Song Gil, North Korea's former acting ambassador to Italy, has left Italy and is being protected "somewhere."

Lee said the spy agency apparently meant a third country but didn't reveal which one. The NIS officials didn't provide a specific answer when asked whether South Korea was involved in protecting Jo, she said. Lee provided no other details.

The NIS told lawmakers in January that Jo went into hiding with his wife in November. But the agency has a mixed record on tracking developments among North Korea's ruling elite, which is made difficult by Pyongyang's stringent control of information about them.

North Korea, which is extremely sensitive about high-profile defections, has yet to publicly comment on Jo's situation, according to Seoul's Unification Ministry. Some experts believe the North may continue to ignore Jo's apparent defection to avoid highlighting the vulnerabilities of its government while it engages in negotiations with Washington to leverage its nuclear arsenal for economic and security benefits.

Also on Thursday, South Korea's military said it was investigating a North Korean soldier who was found crossing the inter-Korean border through a river Wednesday night and has expressed a desire to defect to the South. Seoul's Joint Chiefs of Staff didn't provide further details.