Thousands of North Korean laborers are effectively toiling as state-sponsored slaves while working on construction projects in Qatar, according to an investigation conducted by The Guardian.

According to the report, North Korean laborers working in the oil-rich emirate receive almost no remuneration in person, with their salaries remitted back to North Korea via the recruitment firms that employ them.

The paper quoted a former North Korean army officer who escaped the country in 2005 as estimating that authorities in the country typically keep 70 percent of the total salary earned by workers abroad, and that after fees for food and accommodation are deducted, worker's will only retain 10 percent of their earnings.

One North Korean worker that the paper gathered testimony from said: “We are here to earn foreign currency for our nation.”

Allegations of forced labor against North Korea are not new. The country's entry in the CIA World Factbook states that “many North Korean workers recruited to work abroad under bilateral contracts with foreign governments are subjected to forced labor and reportedly face government reprisals if they try to escape or complain to outsiders.”

North Korea has been subject to wide-ranging international sanctions over its nuclear program, and human rights abuses that were detailed in a damning United Nations report in February.

The country, which has also been plagued by drought and famine in recent years, has a few ways to legitimate ways to earn much-needed foreign currency. In the past, the country has been accused of manufacturing counterfeit cigarettes and even counterfeit U.S. currency in attempts to boost its foreign currency reserves. The country has also been involved in the international trafficking of heroin and methamphetamine, according to the CIA.

Qatar, which is due to host the 2022 FIFA World Cup, has faced widespread criticism for its treatment of the tens of thousands of migrant laborers the Gulf state employs in its booming construction industry.

According to a report by Human Rights Watch, migrant workers in the country are subject to a labor system that facilitates trafficking and forced labor. In contravention of Qatari law, workers have their passports confiscated by their employers, and the kafala [sponsorship] system ties a migrant worker’s legal status to a sponsoring employer, requiring workers to get an exit visa from that sponsor to leave the country.

Qatar has a population of approximately two million people, but only roughly ten percent of those are Qatari citizens. According to a U.S. State department report, 94 percent of the country's workforce are migrants.

In preparation for the 2022 World Cup, the country is spending U.S. $100 billion on infrastructure projects, according to the Business and Human Rights Resource Center. In May, the Qatari government admitted that almost 1,000 migrant workers had died many from cardiac arrests, in the preceding two years.

A spokesperson for Qatar's ministry of labor and social affairs said in a statement, quoted by the Independent, that it takes all issues around worker payment extremely seriously, stating that there are 2,800 North Korean guest workers registered in the country, and it has had “no recorded complaints” about their pay or treatment.

“Qatar is determined to continually improve labour conditions for all who work in the country, and will continue to work with NGOs, businesses and other governments to achieve this,” the statement said.