Jeon Wook-pyo, 68, was one of 25 crewmen on board two boats captured by North Korea in the Yellow Sea in 1972, according to Choi Sung-yung of the Abductees' Family Union.
Jeon, who fled North Korea in early August, is the only one of the crewmen to have escaped, Choi said.
Kim Hyung-suk, a spokesman with South Korea's Unification Ministry, which is responsible for inter-Korean affairs, confirmed to reporters in a briefing today that the man had safely returned to the South but provided no other details.
Jeon underwent two weeks of investigation by government officials before being reunited with his family this month, Choi said.
North and South Korea have lately begun diplomatic talks after trading threats of war in March and April. They're set to reopen operations at a jointly run industrial park, located just north of the heavily armed border separating the two Koreas, and plan reunions this month of families divided by the Korean War.