The son of a high-profile South Korean defector to Pyongyang has now made the same journey, according to North Korean state media.
North Korea says the son of the highest-profile South Korean ever to defect to the North has arrived there to permanently resettle.
The state-run Uriminzokkiri website says South Korean national Choe In-guk arrived in Pyongyang on Saturday to dedicate his life to Korean unification at the guidance of leader Kim Jong Un.
The website published photos showing Choe reading his arrival statement at Pyongyang's international airport.
South Korea's Unification Ministry says it believes Choe is in North Korea without special permission from the Seoul government to visit the North.
Choe is the son of former South Korean foreign minister Choe Dok-shin, who defected to North Korea in 1984 with his wife after political disputes with then-South Korean President Park Chung-hee.
He died in 1986.