From a thriving industry in southeast Asia, the catch might end up on dinner plates almost anywhere in the world.

But you might be shocked to know how these fish are caught. Sometimes the boats are floating prisons crewed by slaves.

In this video report above, CNN's Dan Rivers explores the story of brothers Pheum Dina and Pheum Bolin, who were lured from Cambodia to work on the fishing boats three years ago. They say they were imprisoned on a Thai trawler for 3 months – with no pay and no chance to escape. They were slaves at sea.

Read Enslaved on 'ghost ships' at the CNN Freedom Project