Great White Devoured by 'Mystery Sea Monster'? Scientists Searching for Beast That Killed 9-Foot Shark (VIDEO)

(Photo: Reuters/Mike Hutchings)A Great White Shark swims past a diving cage off Gansbaai about 200 kilometres east of Cape Town.

A great white was devoured by a mysterious and savage creature 11 years ago, and now scientists' hunt for the creature is being filmed for a documentary. "Hunt for the Super Predator" will air on the Smithsonian Channel and will show Australian researchers discovering what possibly could have annihilated a 9-foot shark.

The great white shark that was devoured in the Southern Ocean had been wearing a tracking device placed there by scientists. Four months later on Christmas Eve, the shark's tag plummeted 100 feet down to 2,000 feet below sea level, and the tag later washed up on Australian shores.

"The question that not only came to my mind but everyone's mind who was involved was, 'what did that?'" Dave Riggs, a cinematographer who worked on the film, said in a clip. "It was obviously eaten. What's gonna eat a shark that big? What could kill a 9ft great white?"

The temperatures at 1,900 feet below had been about seven degrees Celsius, but suddenly jumped up to 25C at the time of the shark's death. That led researchers to believe that the great white had been eaten by an animal much larger.

"Looking at the profile of the animal that ate it, 26 degrees, that's pretty high but not enough to be a mammal but it's something seriously huge to sustain that temperature - the larger the animal, the more capable it is of an elevated temperature," Riggs said.

Based on that, researchers have theorized that the "mystery sea monster" could be a "colossal cannibal great white shark," among other guesses. Either way it must have been huge in order to take on Alpha, the 9-foot great white shark.

"When she first came in, she came in with a real swagger," Riggs, who shot the tagging process, explained. "She was three meters long, didn't have a mark on her."

He hasn't ruled out a gigantic cannibal shark or other monsters of the deep.

"The notion of gigantism is well documented in species, to me that plausible," he said.

The Smithsonian's "Hunt for the Super Predator" is based off of Australian documentary "The Search for the Ocean's Super Predator" and it will air on June 25. To see a trailer, click below.