Seafood that winds up in grocery stores in the U.S., U.K., and other industrialized countries is the direct product of the work of slaves in Asia, according to a stunning 2014 report released by The Guardian.

According to the report, the suppliers of fishmeal, which companies feed to shrimp, use slaves on fishing boats, subjecting men to such cruel working conditions as years at sea, 20-hour shifts, and beatings for failing to perform up to task. In a story filed by CNN, a 40-year-old Thai man named Samart Senasook who finally escaped the life of slavery, said he had his identity stolen after signing a one-year contract, only to spend six years at sea.

"There were times, I was about to jump into the sea to kill myself," Senasook told CNN. "My friend from the engine room held me back. Otherwise I would have been dead by now."

According to The Guardian, the top four global seafood retailers all do business with the supplier that interacts with slavers: Walmart, Costco, Tesco, and Carrefour. The supplier is Thailand's Charoen Pokphand (CP) Foods. CP foods made $33 billion in revenue in 2014, according to the report.

CP's U.K. managing director, Bob Miller, said the issue is a real one. "We're not here to defend what is going on," Miller told The Guardian. "We know there's issues with regard to the material that comes in, but to what extent that is, we just don't have visibility."