Queensland Police believe a man's size 10 black running shoe could be key to solving the murder of Cooktown mum Donna Steele.
The shoe was found around the time Ms Steele's body was discovered at a popular fishing spot, four days after she vanished on August 2.
Police have appealed for information to identify the owner of the size 10 man's black Champion Gusto running shoe.
Detective Acting Superintendent Geoff Marsh says the shoe has been extensively examined and finding the shoe's owner is a priority for investigators.
"We would like to now move forward and find out the ownership so that the investigation can generate new lines of enquiry or we can dismiss the shoe," he said.
Described as a "shoe of interest", it is the first item police have released to the public in an attempt to solve the case.
Hundreds of items have been seized by police and sent for forensic and DNA testing, and there have been multiple appeals for public information.
We are extremely confident someone in Cooktown knows what happened to Donna Steele."
"I have some very experienced, senior investigators in Cooktown who are extremely frustrated by the slow progress of the investigation," Supt Marsh said.
"That frustration is nothing compared to the anguish that Donna's family feels.
"It's now coming on three months and her murder remains unsolved."
Police still believe information is being held by a loose-knit group of people out of loyalty to each other.
"They are staying together quite strongly," he said.
"We are extremely confident someone in Cooktown knows what happened to Donna Steele."
There are 16 investigators in Cooktown who will not leave until all inquiries have been exhausted.
Anyone who recognises the shoe or knows of a person who has worn a shoe matching its description in the Cooktown area, on or about August 2, is urged to contact police.Suggest a correction