Chinese fishing fleets are allegedly using North Korean forced labor, a potential breach of international sanctions, with workers allegedly kept at sea for up to a decade, according to a new report by the U.K.-based Environmental Justice Foundation (EFJ).

According to The Guardian, the EJF report, published on February 24, has identified at least 12 Chinese deep-water fishing vessels that employed North Korean crew between 2019 and 2024.

Strict international sanctions on United Nations member countries aim to curtail North Korea’s program of exporting labor and goods to raise funds for its weapons programs.

The report alleges that some North Korean crew were kept at sea for up to ten years, transferred from vessel to vessel and often temporarily transferred to other ships to avoid being detected at foreign ports, with their salary given to the North Korean government. It is one of several forms of forced labor which the UN office of the human rights high commission says has become “deeply institutionalized” in the closed-off, authoritarian country.

EJF identified the North Korean crew through photos, video, and interviews with 19 Indonesian and Filipino fishers who worked alongside them in the Indian Ocean.