South Korea's efforts to help North Korean defectors adapt themselves to its capitalist system have been called into question as an increasing number of them return to their communist home country.

North Korea's state-run television station reported a day earlier that a defector family of three members and another woman defector have recently returned to the North after living in South Korea for a while.

Referring to a news conference held by the four in Pyongyang, the North's TV report claimed that those returnees were lured by the South to defect.

A Seoul official on Friday confirmed the North's TV report about the latest returnees, saying that concerned government authorities are investigating the background of their return.

The four brought to 10 the total number of North Koreans who have returned home after defecting to South Korea since 2000.

Last year, North Korean media reported that a three-member family and two other defectors returned home after living in South Korea, rekindling an ideological warfare between the two countries.

Seoul's Unification Ministry handling inter-Korean relations said in a briefing on Friday that the latest group of defectors seem to have gone back involuntarily, indicating that the North could have been behind their return.

The case also raised skepticism over Seoul's efforts and systems in helping and supervising North Koreans as they resettle in the South.

Local reports said that the government apparently was not aware of the latest return of the North Korean defectors until the North's media reported it.

Under the current system, North Korean defectors are supposed to be put under government supervision for the first five years, but some of them were found to have gone back to the North before the five-year watch period ended.

Nearly 24,000 North Koreans have settled in South Korea after fleeing their homeland since the Korean War ended in 1953.

"The resettlement system is not 100 percent perfect, but (the ministry) is making its utmost efforts," Unification Ministry spokesman Kim Hyung-suk said, adding that officials are reviewing the monitoring system.

(Yonhap News)