LONDON (AFP) - UN investigators probing human rights abuses in North Korea heard harrowing evidence in London on Wednesday from people who have managed to flee the secretive Stalinist regime.

The landmark UN rights commission heard from a handful of defectors who have reached Europe after similar hearings were held in Seoul and Tokyo.

Mr Jihyuan Park, a softly-spoken, bespectacled woman in her thirties, wept as she told how she managed to cross the border into China in 1998, only to be sold as a "wife" to a Chinese gambler and his family.

"The first thing they told me was that, since they'd bought me, they could do anything to me," she told the panel through a translator.

Ms Park, who fled North Korea after her soldier brother got in trouble for his business activities, gave birth to a son in China but was then arrested and told she would be sent home without him. Soon after, she heard her "husband" haggling with a trafficker over a price for the boy.

"Because he was born in such a harsh place, I wanted him to become really strong," she told the hearing, sobbing quietly. "So I named him Steel." Ms Park was sent back and, like other would-be defectors, placed in a detention camp and made to perform hard labour.

But she eventually managed to return to China and find her son, who to her enormous relief had not been sold to traffickers. From there she made her way to Britain, where she is now seeking citizenship.

Another defector, Song Ju Kim, told of his four attempts to flee North Korea - which he made, he said, "because I didn't have any food".

Famine killed hundreds of thousands of North Koreans during the 1990s, and millions still depend on food aid.

Mr Kim told of how, wracked by hunger, he made his first attempt to cross the icy Tumen river into China in March 2006.

Caught almost immediately by the Chinese army, he was handed back to the North Koreans and beaten to a degree he described as "below human".

The 40-year-old described a detention centre where he witnessed terrible beatings, was ordered to search through prisoners' excrement for money they were believed to have swallowed, and where inmates were not allowed to stand up.

"The North Korean prison guards were telling us that once you get to this prison you're not human, you're just like animals," he said through a translator. "And as soon as you get to this prison you have to crawl, just like animals." He eventually managed to escape to China on his fourth attempt and came to Britain with the help of missionaries.

Two former soldiers, meanwhile, told of how army officers turned a blind eye during the famine when their troops looted food from civilians.

Ex-soldier Joong Hwa Choi, 41, said it was returning to civilian life during the horrific food shortages - which claimed the lives of his three brothers - that convinced him he had to leave.

"I really thought I could live decently if I tried hard," he told the hearing. "But when I buried three of my brothers, I felt something was terribly wrong." Pyongyang has refused to grant the UN commission access to the country and has described the dozens of defectors who have given evidence as "human scum".

Led by retired Australian judge Michael Kirby, the team is the first UN expert panel to officially investigate human rights abuses in North Korea.

Two days of further hearings are due to be held in Washington on Wednesday and Thursday next week.

The commission is due to present its final report to the UN Human Rights Council in March next year.