Traffickers (2012)

After his best friend dies in an unexpected accident, black market dealer Young-gyu decides to wash his hands off his illegal activities and start a new life with his girlfriend Yu-ri. But his dream stalls when he learns that Yu-ri needs money for her father's surgery. To help her out, Young-gyu decides to do the job one last time. His smuggling ring operates out of a boat that runs between Korea and China, picking victims from its voyager pool and harvesting their organs. Meanwhile, a married couple, Sang-ho and Chae-hee, boards Young-gyu's passenger boat heading to Weihai, China. That very evening, just when the boat enters international sea waters where countries' laws cannot be enforced, Chae-hee goes missing and all her pictures and belongings vanishes without a trace. Young-gyu finds Yu-ri on the same ship, and she claims to be the only witness to Chae-hee's disappearance.

Source: TMDb