VANISHINGS: The Missing Prime Minister

Shortly after midday on December 17, 1967, Australia's Prime Minister Harold Holt made his way down to the beach for a swim.

Onlookers said that as a large wave swept over, Holt seemed to disappear. Despite extensive air and sea searches, Holt's body was never found.

After his disappearance, rumors circulated that Holt had been a spy, and had been taken away by a Chinese submarine. Could this be true?