Story highlights Oh Kil-nam defected from North Korea 25 years ago, but his wife and two daughters remain behind

South Korean and Swedish governments have tried to intercede on his behalf

First and only communication from family was in 1991; believed held in notorious prison camp

"I made such a foolish decision which has caused my family to suffer such hardship"

Oh Kil-nam refuses to keep a single photo of his family in his home. He says it's just too painful.

For more than 25 years, Oh has lived with the guilt of knowing his wife and two daughters are being held against their will in North Korea because of a choice he made.

"I made such a foolish decision," Oh says, "which has caused my family to suffer such hardship in the hands of an outrageous criminal organization. It doesn't help even if I repent, my heart is torn with sorrow."

Oh, a native of South Korea, moved his family to Pyongyang in 1985 despite his wife's reservations on the promise of a good job and free medical treatment for his wife's hepatitis, but when they arrived he realized he had been tricked.

He says there was not a job nor medical help for his wife, just three months of what he calls, "lectures from day to night on North Korea ideology, history and brainwashing." He was then forced to work in a radio station broadcasting propaganda.

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Oh was sent to Denmark the following year to lure more South Koreans to the communist state. But when he arrived at customs, Oh handed them a piece of paper asking to defect. Held for two months in detention in Germany, he was questioned by different intelligence agencies, including he says the CIA. He was then freed and moved to South Korea.

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But his nightmare had only just begun.

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Oh learned his wife and daughters, only aged 6 and 9 when they first moved to North Korea, were sent to a concentration camp as punishment for his defection. In 1991, he received the first and last message from them.

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Three black and white photos and recorded messages from his family. Oh and the human rights workers believe they were recorded by North Korean officials as a trap to lure him back.

His youngest daughter says, "I miss you dad, I don't know you and I need to grow up fast so I can help mum and I feel regret but now I can lift water buckets and wood very well." Studying the photos, some defectors have told Oh they believe they were taken in the notorious Yodok concentration camp.

His eldest daughter tells him, "Hi dad, it's Haewon, I dreamt the other day that I was celebrating my birthday with you. I miss you. It's been a while since I said the word father and my tears are falling."

On the tape, his wife wonders when she will see him again.

Oh looks at the photos of his family. Thinking back to when he first received them he shakes his head. "I am ... psychologically and physically, totally destroyed," he says. "I have literally no feeling."

He says he feels helpless and all his hopes now rest with the United Nations and the South Korean President. The UN body on arbitrary detention has petitioned North Korea to release the family, saying their detention is "arbitrary," but the response has not been positive.

Pyongyang claims Oh's wife has already died from her hepatitis and his daughters want nothing to do with him as they say he deserted them. Oh refuses to believe either claim.

South Korea has increased diplomatic pressure on Pyongyang. President Lee Myung bak asked the Swedish King, Carl Gustav for assistance. Sweden has an embassy in Pyongyang and has, in the past, acted as a neutral broker for countries with no presence there.

All Oh can do now is wait -- as he has for the past quarter of a century. And hope he will live to see his daughters freed.

"Every night I have nightmares,' he says. "I'm more than 70 years old now and exhausted but I will stay alive until I can hold my two daughters again."