Some 4,000 North Koreans are estimated to be working at major construction sites in a suburb of the Kuwaiti capital and living in military-style camps run by the North's government, a Seoul diplomat said Monday.

Impoverished North Korea has recruited its people to work abroad and reportedly kept most of their earnings, one of the few sources of hard currency for the isolated regime. Along with China and Russia, the Middle East is a major destination for North Korean laborers.

"We have figured out that there are around 4,000 North Koreans working at major construction sites to build homes, hospitals and other facilities in a suburb area of Kuwait City, including Jahar," the diplomat said on the condition of anonymity.

A North Korean worker in Kuwait earns up to US$500 per month, but nearly four-fifths of the worker's monthly salary is directly deposited into accounts controlled by the North's government, according to the diplomat.

"A North Korean worker is believed to actually receive $100 per month, with their jobs ranging from plasterers, carpenters, welders to drivers at the construction sites," the diplomat said.

In April this year, eight North Korean workers were arrested by Kuwaiti authorities for allegedly bootlegging alcoholic beverages, the diplomat said. Alcohol is illegal in Kuwait, making the illicit business of alcohol bootlegging highly profitable.

A U.S. State Department report on North Korea's human rights conditions said that many North Koreans working overseas were subjected to forced labor, with their movement and communications constantly under surveillance and restricted by North Korean government "minders."

"These workers faced threats of government reprisals against them or their relatives in North Korea if they attempt to escape or complain to outside parties," the report said.

"Workers' salaries are deposited into accounts controlled by the North Korean government, which keeps most of the money, claiming fees for various 'voluntary' contributions to government endeavors."(Yonhap News)