The freshwater crocodile was found in the Thomson River downstream from Longreach a few days ago, hundreds of kilometres from where the reptiles normally live.

‘‘Two fellows from Longreach, two local fellows, went out doing their regular yabby run and they have come across probably a three-year-old freshwater croc,’’ Longreach Recreational Fishing Club member Cheryl Taylor told the ABC on Monday.

‘‘So they quickly flipped it into the boat, took photos and put it back, which is the legal practice.’’

She said the croc seemed at home in the river and would be left there as freshwater crocodiles don’t pose a threat to humans.

‘‘I have no idea how he got there. I don’t think he has come down in a flood or anything, I think someone might have taken him home at some time and he has got away.’’

The find has sparked huge interest on social media, after the club posted pictures of the croc on its Facebook page.

Freshwater ecologist Dr Adam Kerezsy said other crocodiles had been found in inland areas in recent years, and there were really only two explanations: floods or human intervention.

‘‘I favour the human-assisted dispersal theory. My quiet suspicion is it has come via four wheels ... and I have said this every time we have had sightings of crocodiles in the western rivers,’’ he told the ABC.

‘‘If that is what is happening, I am sure (someone) is deriving a bit of amusement from it, but it is not really a very sensible thing to do and it’s probably not that fair on the animals either.’’