The Vanished (2006)

A young reporter is covering the mysterious case of a child found dead with missing internal organs. Suspecting a case of organ trafficking, he visits the doctor who was responsible for the autopsy; and finds that the organs were not stolen after all - they were missing from the start. Tracing the body back to a remote area in the woods, he starts to unravel the story of a group of children who went missing 35 years ago... yet reappear every time it rains, seeming not to have aged a day since their disappearance...