Queensland Police said they found human remains, in addition to clothing and a walking stick belonging to Anne Cameron, who was reported missing Tuesday from a facility in Port Douglas, Sky News Australia reported.
Fellow resident Judith Wright said she saw Ms Cameron walking towards the facility's administration building shortly before 4:00 on Tuesday, the day she disappeared.
"We would like to sincerely thank the Police, SES, Fire Brigade and everyone in the Port Douglas community who helped us in the search for Anne", she posted to a Port Douglas Facebook page on Thursday afternoon.
Acting Inspector Ed Lukin said: 'We located a number of items, including clothing that we believe belong to the missing person, we also located a walking stick with her name on it'.
"It is my deep regret to inform you that following an extensive search and the discovery of certain items as a result of that search, we have the firm belief that my nan Anne Cameron has passed away in tragic circumstances", Anne's granddaughter Isabella Eggins wrote.
"Those items are now being tested in Cairns and we expect to see results tonight or tomorrow".
State Emergency Service area controller Sean McGuinness said the search is proving to be hard.
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A Department of Environment and Heritage Protection spokesman says traps will be set in an attempt to catch the crocodile as police and wildlife officers continue to look for the woman's body.
Surveillance will be conducted on water and on foot on Thursday night.
Police said the remains found at Port Douglas have been sent for further testing, but there is no indication of foul play.
"She didn't appear to be anxious about anything", she said.
It was understood Anne Cameron went for a swim in an area inhabited by crocodiles.
"She's only been here eight or nine days".