Scientists have been left baffled after a nine-foot great white shark appears to have been eaten by a much larger animal.
Researcher in Australia tagged the shark as part of a study, but it washed up dead on a beach four kilometres away two months later.
After checking the information on the tracking device, they found the shark had suddenly plunged to 1,900 feet deep into the ocean.
Soon after, the tag saw a rapid temperature rise, the kind you may find inside a digestive system.
The tag stayed at that depth and temperature for a number of days, before it surfaced and washed up on shore.
Scientists can only think the shark may have been eaten by a bigger "colossal, cannibal great white shark", reports the Mirror.
They suggest the shark would need to have been 16 feet long and weigh two tonnes to have beaten the nine-footer.
The case is detailed in an upcoming US documentary by the Smithsonian Institute, called the Hunt for the Super Predator.
According to news.com.au, filmmaker Dave Riggs says in the documentary: "When I was first told about the data that came back from the tag that was on the shark, I was absolutely blown away.
"The question that not only came to my mind but everyone's mind who was involved was, 'what did that?' It was obviously eaten. What's gonna eat a shark that big? What could kill a [9-foot] great white?"