N.Korea's Restaurant Empire Overseas

North Korea operates around 130 restaurants around the world and earns around US$40 million a year from those businesses each year, intelligence agencies estimate.

Around 90 of them are in China, nine in Russia, seven in Cambodia and four in Vietnam. Their number has increased recently as various North Korean agencies competed to raise foreign currency after Kim Jong-un came to power.

Each restaurant hands over around $300,000 a year to the regime, so they are de facto fronts for the state to generate funds for the nuclear and other weapons programs.

North Korean authorities usually select staff from among the children and relatives of party or military officials. They are usually young women with training in dancing and music.

One high-ranking North Korean official who defected to South Korea said, "The workers are chosen among the children or relatives of families in good standing because they are believed to be less vulnerable to being influenced by the outside world."

But as demand for pretty young women increased, they have been drawn from a wider pool with less emphasis on family background.

They work under strict surveillance just like other North Koreans laborers abroad, living in collective accommodation and prevented from traveling freely in their host country. If they do leave their quarters they must travel in groups of three or four and are not allowed to use mobile phones.

They earn anywhere between $150 and $500 a month depending on how well they can dance and play an instrument. They also get tips, so their income is relatively high by North Korean standards, which makes the positions a dream job for many young people.