Story highlights U.N. human rights officials says numbers of North Koreans working abroad have grown

They are believed to get little or no pay, with Kim Jong Un's regime taking the lion's share

Companies employing the workers "become complicit" in forced labor scheme, U.N. says

(CNN) North Korea's catalog of abuses against its own people within the secretive country's tightly controlled borders has been widely reported. But Kim Jong Un's regime is also believed to be pocketing huge sums from tens of thousands of its citizens who are sent abroad to toil in forced labor conditions, the United Nations says.

The laborers are made to work as long as 20 hours a day without enough food and under constant surveillance, according to a new report from Marzuki Darusman, the U.N. special rapporteur on human rights in North Korea.

He told a news conference Wednesday that the practice has become more visible in recent years and that "the numbers have grown."

"I think it reflects the really tight financial and economic situation in the North," Darusman said.

The overwhelming majority of the workers are employed in North Korean allies China and Russia, according to the report. But the rest are spread across a range of countries in Asia, the Middle East, Africa and Europe.

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