Queensland wildlife rangers are searching waterways on North Stradbroke Island (Minjerribah) off Brisbane after the sighting of a large saltwater crocodile on Wednesday and further reports of sightings on the mainland on Thursday.
Local tour operator Mark Jones said he spotted the crocodile at the springs on Wednesday at 7.45am while he was starting his tour.
"The customer was leading out of the creek and we stopped outside the creek and then started talking about the location," he recounted.
"It raised its head and body out of the water and like, one of the other fellas seen it, and I seen it, and said nothing.
"I saw something out there but just watched the ripples to see if it would come up again and sure enough, it came up again another two times.
"They're pretty easy to detect, there's an eye shine you can see certainly at night time."
Mr Jones said this was the first officially reported sighting, although he has heard of other sightings over the years.
"I got a message from my nephew last night about a couple of fellows who saw it at Wellington Point back in September, a croc over there," he said.
"They were in their 20s so they're not going to say nothing because no-one would believe them."
Mr Jones's sighting has triggered an investigation from the Department of Environment and Science.
Rangers flown in from north Queensland to help with search
Rangers from north Queensland, with experience in crocodile management, have been flown down to help with the search.
Three boats went out on Thursday to search waters on the eastern side of the island and drones are also being used.
Jacob Martin, a Quandamooka ranger in charge of the search, said the crocodile could be anywhere from 2.5 to 4 metres.
"It was sighted just out the front of Myora Springs by one of our local custodians," he told the ABC.
"He lived up north for many years so he's got plenty of experience of crocs."
But Mr Martin said there had been no reported sightings since Mr Jones's.
"We got our whole ranger force out on the search, which is between 10 to 17 rangers," he said.
Mr Martin said there had also been an alleged sighting at Manly, on the mainland in Brisbane's east, which would be unusual.
"If it wasn't my boss that came to get me, I would probably not have got out of my office chair, I would have said to the rest of the rangers go be serious somewhere else.
"But very rare, very unusual but exciting."
Crocodile sightings this far south in Queensland are highly unusual, and the typical habitat begins at the Boyne River south of Gladstone, and extends up the north and to the east across Far North Queensland.
"Some people are calling us crazy," Mr Martin said.
"Others are coming through with stories of sightings over the years, elders are telling us stories of sightings over the years.
"There's a lot of people here that think it isn't true, and a lot of people believe it. Mixed emotions.
"Where it was found is a very popular swimming hole for our people, very sensitive site, our little ones are here all the time."
The Queensland Department of Environment and Science said any crocodile found in the search would be relocated further north.
"I believe once we get a more accurate sighting of it, that will give the experts a better idea where to set some traps and to hopefully relocate it back to his country," Mr Martin said.
