SEOUL (Yonhap) — North Korean workers in the eastern Siberian region earn a mere US$200-3,000 a year on average, often exposed to a delay in payment due partly to corruption among managers, a report showed Wednesday.

It adds to renewed international attention to tens of thousands of North Korean workers now toiling in Russia, China and more than a dozen other nations. Marzuki Darusman, U.N. special rapporteur on North Korea, recently told a U.N. General Assembly panel that they are “under overall conditions that reportedly amount to forced labor.”

According to the new report by Lee Chang-ho, professor at Hanyang University in Seoul, the annual income of North Koreans working in the Maritime Province of Siberia, close to the Russia-North Korea border, is $200-3,000 excluding taxes.

“A delay in payment is frequent,” said the report based on on-site surveys and interviews with North Korean defectors.

In contrast, North Korean managers there make $50,000-100,000 per year by taking bribes or running private businesses, it added.