No sign of reported crocodile off Brisbane

The mystery sighting of a three-metre saltwater crocodile off the coast of Brisbane, more than 400 kilometres south of its habitat range, is yet to be confirmed by authorities.

Queensland rangers have been looking for the marine reptile near Myora Springs on Stradbroke Island, also known as Minjerribah, after Quandamooka man Mark Jones spotted it while leading a kayak tour on Wednesday.

Three vessels are searching waters on the eastern side of the island, and rangers are also using drones, a Department of Environment and Science spokesman told AAP.

"The Queensland Parks and Wildlife Service has flown two experienced crocodile management wildlife officers from North Queensland to assist in the investigation," the spokesman said.

Visitors and residents on Minjerribah are urged to avoid the search area to allow rangers and wildlife officers to investigate.

Members of the public are asked not to launch private drones on and around the island while the investigation continues.

If there is a crocodile, it would be in an area classified as an atypical habitat zone and removed regardless of its size under the state government's management.

Crocodiles aren't known to venture so far south in Queensland, with Minjerribah about 440km south of their regular habitat range.

Bond University marine scientist Dr Daryl McPhee said if the animal was found, it would be "exceptionally rare" and a "one-in-one-hundred-year event".

"The person who reported it ... is highly credible. He's a local traditional owner but also somebody who's spent a lot of time on the water, so I certainly put some credibility in what he's seen," he told AAP on Wednesday.

"It is feasible but obviously exceptionally rare for a crocodile to be this far south."

Dr McPhee said a crocodile was shot dead on the Logan River in 1905 but was rumoured to be a released pet.

He said this one could have been released, although it was unlikely, or it could have drifted from the most southerly known range of crocodiles in Hervey Bay.

Crocodiles can move large distances at sea, he added, particularly after floods.

The scientist also wondered how long a crocodile could have been at Minjerribah before it was spotted, and what a large three-metre animal could feed on in the area.

"So certainly any dogs in the area might have been at risk," Dr McPhee said.

There were 41 crocodile attacks on humans, 12 of them fatal, in Queensland between 1985 and 2021.