The successful search for the Titanic wreckage was actually a cover up for a secret US naval mission, according to CNN.

Robert Ballard, who found the Titanic wreckage, told CNN the expedition was actually part of a secret US military mission to recover two sunken nuclear submarines on the bottom of the ocean.

The US military wanted to find the nuclear submarines before the Russians could get to them.

SCREENSHOT/GEOBEATS The wreckage of the Titanic, which sank in 1912, was discovered near the bottom of the ocean in 1985.

"They did not want the world to know that, so I had to have a cover story," Ballard told CNN.

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Ballard, who was a commander in the US Navy and a scientist at the Woods Hole Oceanographic Institution, was offered funding to search for the Titanic but only if he was able to first find the two American nuclear submarines that sank in the 1960s.

SCREENSHOT/GEOBEATS The Titanic departing Southampton on April 10, 1912.

When Ballard and his team found the two nuclear submarines, they only had 12 days left to search for the Titanic.

"When we found the Titanic, we naturally were very excited, because it was a tough job.

"We got it, scoring the winning goal at the buzzer," Ballard told CNN.

The Titanic departed Southampton in England on April 10, 1912 with an estimated 2224 passengers and crew aboard.

The vessel hit an iceberg four days later and sunk. More than 1500 people died.