A U.S. lawmaker has called for investigation into the import of seafood processed by North Korean laborers illegally working in China.

In a hearing conducted by the Congressional-Executive Commission on China (CECC) on Tuesday, Republican Chris Smith strongly criticized China-based companies for exploiting “the forced labor of Uyghurs and North Koreans to process substantial quantities of seafood destined for the U.S. market.”

An investigationby The Outlaw Ocean Project that Smith detailed at the hearing found that difficulties tracing the origins of seafood have led to the use of seafood processed by North Koreans at major American restaurants and wholesalers,