The district court in Suwan, Gyeonggi Province, on Friday sentenced a 59-year-old Jang to four years in prison for undergoing intelligence training to provide information to North Korea.
A 56-year-old woman, Yoo, was also sentenced to three-and-a-half-year in jail for on a similar conviction.
The court said the two convicts have been working with North Korean agents, delivering contents of closed circuit television (CCTV) at locations like the guard post along the east coast.
However, the sentence was reduced in consideration of the fact that they have been involved in various unification projects.
The two made more than 30 trips to China from 2007 to make contact with North Korean agents and even delivered a signed document praising the works of North Korea founder Kim Il-sung.