A photo widely shared on social media showing two men "surfing" on a protected green turtle on an Australian island is being investigated by authorities. The image appears to show two men drinking beer while "riding" the animal on Fraser Island, just off the eastern coast of Australia.

The photo appears to have been shared from a Facebook account belonging to a man named Ricky Rogers with the caption: "Surfed a tortoise on zee weekend.. gnarly duddddeeeee [sic]."

Rogers has since set his social media profiles to private, but the image of the turtle was re-uploaded by Gold Coast resident Matt Wright with the caption: "When your brain is the size of a peanut, your thought process is ridiculous. Share this around and let's see if we can get this fool a nice hefty fine."

The image has since been shared more than 10,000 times.

Queensland Parks and Wildlife Service (QPWS) said it is investigating the photograph and is taking the matter "seriously" but added there is "some evidence to suggest that this turtle was deceased at the time of the photo."

In a message posted on Facebook, QPWS added: "Thank you to everyone who's gotten in touch with us about the green turtle incident. As hard as it is to see that sort of thing, we really appreciate the care you've shown in letting us know.

"We found out about it and reported it straight away to our rangers. They're looking into it right now and they'll be making sure the matter's followed up."

The men in the photo could face a maximum fine of nearly AUS$20,000 (£12,000, US$15,000) under laws against interfering with a natural resource such as a green turtle.

RSPCA Queensland spokesperson Michael Beatty condemned the men in the photo as "complete idiots". He told the Fraser Coast Chronicle: "There's no way they should be doing what they were doing," he said.

"Per usual, they've been idiots and posted it on Facebook...hopefully people on Facebook will let them know what idiots they were."