By Jung Sung-ki
Staff Reporter

The military is closely monitoring about 50 soldiers suspected of conducting spy activities or believed to be highly exposed to North Korea's espionage operations in the South, an official of the Ministry of National Defense said Sunday.

The remarks came a day after the Dong-A Ilbo newspaper released a picture of a memo taken during a hurriedly-arranged meeting of top military brass chaired by Defense Minister Lee Sang-hee, following the arrest of a female North Korean spy suspect.

The memo written by an unidentified official presumed to be a member of the Defense Security Command, the military's intelligence and counterespionage agency, says there are about 50 ``suspects who have infiltrated the (South Korean) military.''

Military authorities have investigated some 100 espionage cases involving South Korean soldiers, it says.

The ministry official said, however, the word ``suspects'' doesn't necessarily mean they are active North Korean agents, like the arrested female spy, Won Jeong-hwa, who disguised herself as a North Korean defector and passed classified information to North Korea's security agency through contacts with active South Korean military officers.

``The `suspects' described in the memo refers to those who have relatives in North Korea or are working in an environment that has easier access to the North,'' the official said, asking not to be named. ``It's not new that the military is carrying out such counterespionage operations, including monitoring suspects.''

The memo also says the military is monitoring about 50 suspects who allegedly leaked classified information and there are some 170 ``leftist forces'' serving in the military.

During Thursday's meeting, Defense Minister Lee directed his top commanders to implement measures to prevent enlisted soldiers or officers from being seduced by North Korean spies.

``The incident proves North Korea is still making strenuous efforts to communize South Korea and their spy activities are rampant in our society,'' Lee said. ``Anyone in the military should recognize he or she could be a target of North Korean agents.''

Won, 34, is the first North Korean spy to be arrested in South Korea since 2006, and the second in a decade. Security experts say the decade-long ``sunshine'' policy of engaging the North under the previous liberal South Korean governments has helped loosen the sense of anti-communism of South Korean troops.

Won seduced active military officers or non-commissioned officers under the direction of a North Korean intelligence agency, according to prosecutors. She met the soldiers while delivering anti-communist lectures at military bases or through wedding agencies.

She gathered and passed classified information to North Korea, including the locations of key military installations and lists of high-profile North Korean defectors since 2001.

``There is a consensus in the military circle that South Korea should take the latest female spy case as an opportunity to fix lax anti-communism among its troops,'' another ministry source said.

South and North Korea remain technically at war, since the 1950-53 Korean War ended in a truce, not a permanent peace treaty.

gallantjung@koreatimes.co.kr