The former North Korean spies and guerrillas, mostly in their 70s, were imprisoned for decades in South Korea where they are described as "long-term prisoners." They are free now, but cannot leave the country without government approval.
In a goodwill gesture following the historic inter-Korean summit in 2000, South Korea repatriated 63 former North Korean spies and guerrillas who were caught after the Korean War ended in 1953.
Pyongyang called for the release of all North Korean prisoners who hope to return home, but South Korea insisted it held no more spies wanting to be repatriated.
South Korean local civic groups also claim there are nearly 30 more former North Korean spies wanting to go home to spend the rest of their lives with their families.
"We are reviewing their repatriations," said Yoo Jong-ryol, a director in the Unification Ministry that handles Seoul's policy towards Pyongyang. "We are in consultations with the Justice Ministry and other related government agencies," he said.
But anti-communist activists called on the Seoul government to win a reciprocal action from North Korea, which detains hundreds of prisoners from the Korean War, and other South Koreans against their will.
More than 19,000 South Korean soldiers were missing at the end of the Korean War. The Defense Ministry estimated there are more than 500 POWs still alive in the North. In addition, there are an estimated 480 South Korean civilians who have been abducted by the North.