A North Korean defector interrupted a United Nations human rights press conference in Seoul on Thursday to plead tearfully to be allowed to go back to her relatives in Pyongyang.

More than 30,000 North Koreans have fled poverty and repression in their isolated homeland to move to the South.

But they often struggle to make a living in the capitalist South and sometimes fail to adjust to their new lives.

Dressmaker Kim Ryon-Hui arrived seven years ago but has since has made several desperate attempts to return to her family - including forging a passport, for which she was imprisoned, and falsely confessing to espionage in the hope she would be expelled.

"I'm a citizen of Pyongyang of the Democratic Republic of Korea," Kim told dozens of reporters at a briefing in Seoul by Tomas Ojea Quintana, the UN's Special Rapporteur on human rights in the North.

"I have been forcefully detained in the South for seven years," she added.

Kim accused Seoul of violating her human rights, saying it had prevented her from going back to her aging parents and daughter.