Police say they "won't rest" in their search for answers after returning to a remote station where a four-year-old boy vanished months ago.
Gus Lamont was last seen by his grandmother playing on a mound of dirt at the sprawling sheep station in outback South Australia on September 27.
Detective Superintendent Darren Fielke said detectives had returned to the property last week and spoken to Gus' family, who were continuing to co-operate with police.
"That is not a simple investigation," the Major Crime chief said on Tuesday.
"It's a four-year-old boy in a remote area. We're exploring all avenues to do with locating Gus. Nothing is off the table.
"We won't rest until we're satisfied that we've done absolutely everything we can to find him, and if we've done everything we can and we can't find him, then that sometimes is what will happen."
The boy's disappearance sparked intensive searches spanning almost 500 sq km by hundreds of people using aerial support and mounted units.
Detectives last week took further statements from the family.
"That's just part of the normal investigational process that we go through," Supt Fielke said.
"They went through a pretty torrid Christmas, obviously, without Gus, and we're checking the family regularly."
In November, search teams focused on six mine shafts near property, 40km south of Yunta, using specialist officers, but found no trace of Gus.
A four-day search within a 5.5km radius of the homestead in early October also concluded without any evidence.
The family previously expressed their devastation over the boy's disappearance in a September 30 statement.
"This has come as a shock to our family and friends, and we are struggling to comprehend what has happened," it said.
"Gus's absence is felt in all of us, and we miss him more than words can express.
"Our hearts are aching, and we are holding onto hope that he will be found and returned to us safely."
