Young female refugees from North Korea are increasingly becoming a commodity in China, where they are sold to farmers for up to 1,500 dollars a head, according to a Seoul campaigner.
The human trafficking is far from new but has become more prevalent as prices soar amid a shortage of Chinese women in the countryside, said Reverend Chun Ki-Won, head of the Durihana Association, which offers aid to refugees.
Chun, who has helped more than 900 North Koreans escape from China, said women are forced to live "like animals" because of Beijing's policy of repatriating the refugees as economic migrants.
"China is now a responsible nation. It should care about national prestige through solving human rights issues," he told AFP.
Men escaping the impoverished hardline North increasingly fall victim to tighter border controls or to bounties offered to Chinese for turning them in.
Women can find safer shelter across the border because of their economic value. Nowadays they make up around 80 percent of the tens of thousands of North Koreans hiding in China, Chun said.
More than 90 percent of them fall victim to human trafficking, he said.
The process starts at the border, where Chinese brokers bribe the North's border guards to let the women through, the 53-year-old pastor said -- usually between 500 and 1,000 yuan (75-150 dollars) for each.
One of two fates awaits the women who make it through: marriage to a farmer, often elderly or disabled, or taking their clothes off for Internet sex shows.
About 20-30 percent are destined for marriage and are resold to another broker for about 2,000 yuan. They are then sold to farmers, normally for 5,000-10,000 yuan, but the trafficking does not necessarily end there.
If the customer does not like his wife, he can resell her and add about 2,000 yuan to the original price. Some women are sold seven or eight times, Chun said.
The women rarely know what is in store for them, Chun said. "Most of the time, they are just told they will get a good job in China and will be able to earn a lot of money."
Women destined to appear on Internet sex shows are promised a job at a "computer company". The reality is confinement in a tiny room with a webcam so they can engage in a "body chat" with clients worldwide.
They earn a maximum of 2,000 yuan per month but most of this is confiscated to repay the cost of smuggling them into China.
Women cannot complain about their treatment for fear of being sent back to North Korea, where they risk harsh punishment.
Children fathered by Chinese men and North Korean women are the biggest problem, Chun said.
"The Chinese government does not recognise children whose mother is not registered. If the mother runs away or is taken back to North Korea, the children are left with nothing -- no nationality, no parents and no identity."
The children can be officially registered if the father pays a fine but most cannot afford this.
The computer stripping does offer a gleam of hope.
"When South Korean clients get in touch with these women, they become friends and help the women find organisations that would rescue them," Chun told AFP.
"Other than the 'chat' itself, women send e-mails or use online message services to ask for help."
China's forced repatriation policy has been strongly criticised by rights groups who say the North Koreans should have refugee status.
At a Washington press conference in April last year, North Korean women who escaped the sex trade in China said brokers there treated them like livestock, selling them on to one or more "husbands".