(CNN) The owner of an Australian crocodile farm has told of his shock after finding a surgical plate in the stomach of a 4.7-meter (15-foot) reptile.

The saltwater crocodile, named M.J., died in June at the Koorana Crocodile Farm near Rockhampton, Queensland, in the country's northeast.

The orthopedic plate was discovered inside the beast's gut, along with various stones used to help grind up food, during an examination into its death.

"Strange things turn up in crocodile stomachs all the time," farm owner John Lever told CNN affiliate 7 News. "But finding a surgical plate in there, well, we never thought we'd find that."

Lever was uncertain whether the plate came from a human or animal.

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