The Associated Press has won the Pulitzer Prize for Public Service for documenting the slave labor trade in the Southeast Asia’s seafood industry.

AP wins Pulitzer for slave labour fish story

The 18-month project involved tracking seafood caught by slaves to the processing plants that supply supermarkets, restaurants and pet stores in the U.S. The investigation spurred the release of more than 2,000 captive workers.

The stories also led to numerous arrests, seizures of millions of dollars in goods, and a crackdown on Thai shrimp-peeling plants.