The man who located the wreck of the Titanic has revealed that the discovery was a cover story to camouflage the real mission of inspecting the wrecks of two Cold War nuclear submarines.
When Bob Ballard led a team that pinpointed the wreckage of the liner in 1985 he had already completed his main task of finding out what happened to USS Thresher and USS Scorpion.
Both of the United States Navy vessels sank during the 1960s, killing more than 200 men and giving rise to fears that at least one of them, Scorpion, had been sunk by the USSR.
Dr Ballard, an oceanographer, has admitted that he located and inspected the wrecks for the US Navy in top secret missions before he was allowed to search for the Titanic.
Titanic: The Final Secret will be shown on the National Geographic Channel at 9pm on June 8.
This is reminiscent of the Hughes Glomar Explorer that Howard Hughes said was intended to mine minerals off of the ocean floor but was really used to recover the sunken K129 Soviet submarine. The effort was only partially successful.