Australian researchers had tagged a healthy shark to track its movements as part of a study.

They were shocked when the tracking device washed up on a beach four months later, just 2.5 miles away.

Scientists found that the data indicated that the shark underwent a 30-degree spike and a rapid 1,900-foot dive. The temperature increase and underwater descent indicate that the shark had entered a larger animal’s digestive track.

“When I was first told about the data that came back from the tag that was on the shark, I was absolutely blown away,” said filmmaker David Riggs in the Smithsonian’s “Hunt for the Super Predator,” which documents Australia’s first large scale great white tagging project. “What could kill a 3-meter great white?”

The documentary will air in the U.S. on June 25.

Click here for the full report from Australia.