North Korea's Ghost Ships

We investigate why fishing ships from North Korea, discovered with dead bodies onboard, are washing up on Japan shores.

A growing number of North Korean fishing boats are washing up on the shores of Japan.

Sometimes there are survivors but often they carry a tragic cargo of corpses from the so-called "Hermit Kingdom".

Shizuo Sato recalls the day he made a grim discovery on Japan's west coast.

"We've known of many ghost ships found in this area," he says. "We all thought that if it's a dead body, it must be a North Korean."

These mysterious "ghost ships" are a diplomatic, logistical and financial nightmare for Japan, costing millions of dollars in police investigations, clean-up operations and repatriation of survivors and human remains.