JUST DONE: Police have just broken open a mysterious box found only 500 meters from the spot where Gus disappeared, and what they discovered inside has left everyone at the scene stunned.

According to reports, the wooden box was partially buried under fallen leaves near a stream, its surface covered with dirt and scratches as if it had been there for weeks. Locals first noticed it early this morning and immediately contacted authorities, who quickly sealed off the area for investigation.

When police carefully pried the box open, witnesses said there was a moment of silence — and then shock spread across every officer’s face. Inside the box was a small piece of clothing matching what Gus was last seen wearing, along with a folded note, protected by a thin layer of plastic. The contents of the note have not been publicly revealed, but sources close to the investigation described it as “something that changed the tone of the entire case.”

Authorities are now examining fingerprints and DNA traces found on the box to determine who placed it there — and whether it was done before or after Gus’s disappearance.

The discovery has reignited public concern and fear, as many now wonder whether this box was a message, a clue, or a warning left behind by someone who knows more than they have admitted. Police have yet to release an official statement, but sources confirm that search teams have expanded their perimeter in hopes of uncovering where this trail might lead next.

When Detective Superintendent Darren Fielke — the officer in charge of SA Police’s Major Crime Investigation Branch — walked into a room of waiting journalists to deliver a press conference, it was the first indication that perhaps the case of a four-year-old missing for months in South Australia’s outback had taken a turn.

Those suspicions were confirmed a few minutes into Thursday’s press conference when Detective Superintendent Fielke announced that he was “declaring the disappearance of Gus Lamont to be a major crime”.

It was a significant shift from previous public police commentary that the prevailing assumption was Gus had simply wandered off from the homestead where he lived near Yunta.

But on Thursday, Detective Superintendent Fielke said there was, at this time, “no evidence, physical or otherwise” to suggest that.

Detective Fielke then spent a good deal of time detailing extensively how police had searched for Gus.

The search for Gus included 160 SAPOL members and 230 non-members. (ABC News: Daniel Taylor)

An ‘unprecedented’ foot search

Detective Superintendent Fielke said there were two elements of the searches for Gus; by foot and through aerial means.

He described the foot search as “unprecedented” with “significant resources”, including 160 SAPOL members, and 230 “non-SAPOL resources” such as the State Emergency Service, Indigenous trackers, and the Australian Defence Force.

As part of the ground search efforts, three dams were searched — with one drained and searched by police divers — along with six mine shafts.

A dam was drained and searched in October as part of the search for Gus. (The Advertiser: Dean Martin)

Overall, Detective Superintendent Fielke said there were eight separate searches that extended to a radius of 5.47 kilometres out from the Oak Park Station homestead — the equivalent of about 95 square kilometres.

The reason for the 5.47km radius, Detective Superintendent Fielke said, was data-based.

“The national search and rescue manual indicates to us scientifically, soundly based statistical data that children aged four to six years of age are located 95 per cent of the time within 5.47 kilometres of their last known place they were seen,” he said.

“It’s not guesswork. It’s based on scientific, factual, reliable statistical data, [which] is why we put the foot search into that area and why we invested so much time and effort into that area in the early part of this investigation.”

Jim Whitehead was instrumental in putting together the National Search and Rescue Manual. (ABC News: Mark Leonardi)

Jim Whitehead spent more than 15 years as Queensland’s search and rescue coordinator, and was instrumental in the development of the National Search and Rescue Manual cited by Detective Superintendent Fielke.

Dr Whitehead, a former senior sergeant who said he had been involved in approximately 15,000 search and rescue operations, compiled the data used in the report.

He said it showed that, in cases involving missing four-to-six-year-olds who were eventually found, 95 per cent were located within 5.47 kilometres of where they were last seen.

“That’s the average distance that children in the past have gone out to,” he said.

“It’s 95 per cent of kids who were reported missing and were subsequently found … aged between four and six.

“There’s always somebody who will go beyond what you think is the maximum distance, but having said that, if they [SA Police] searched all the way out to 5.47km, 5.5km, 8km and they haven’t found him, then I would be very supportive of them saying he’s not there to be found.”

Police conducted eight separate ground searches that extended out to a radius of 5.47km from the homestead. (ABC News: Daniel Taylor)

In addition to the ground searches, Detective Superintendent Fielke said an initial aerial search the night Gus disappeared extended about 12km out from the homestead, and later searches captured images from 10 and 15km radiuses.

He said imagery captured was given to an external AI company that was able to provide “really high definition pictures and footage”, and that was reviewed by Task Force Horizon members.

“This is a capability that hasn’t previously been used by SAPOL,” he said.

‘Not a place you just go to’

In addition to the sheer size of the property, searchers also had to contend with challenging conditions, including temperatures dropping below 10 degrees Celsius at times overnight.

ABC reporters on the ground during the early searches described “blue bush scattering the red dirt as far as the eye can see” and arid scrubland laced with “winding sandy tracks”.

They also described conditions as dusty at times, due to high winds and those searching the property on motorbikes.

On top of that, the station is in a remote location.

When discussing the efforts Task Force Horizon went through to investigate the possibility that Gus was abducted — which he said they “have found no evidence to suggest” is the case — Detective Superintendent Fielke detailed just how remote the property is.

Mounted operations were involved in the search at the remote station. (ABC News: Daniel Taylor)

“It is 45km inland from the nearest main roadway, which is the Barrier Highway,” he said.

“Oak Park Station doesn’t have a signpost or anything like that off a road that points you to Oak Park Station.

“There’s nothing obvious that would lead you to Oak Park Station unless you know where you’re going and the way there.

“It can only be accessed by one of two 45km dirt roads that come in from different directions.”

Those roads, Detective Superintendent Fielke said, can only be accessed by four-wheel drives.

“If you’re driving on those roads, you’re going to one of the stations or you’re lost,” he said.

“It’s not a place that you just go to.”

A map showing the ground search area in blue, and the aerial search areas in red and green. (Supplied: SAPOL)

In addition to the remote location, Detective Superintendent Fielke said several gates, some of them regularly locked, impede access to the station.

“You have to drive past other stations to get to Oak Park,” he said.

“The roads are not a thoroughfare and as I’ve said, if you’re driving on those roads you’re there for a reason.”

A ‘textbook search’

Despite the mammoth search efforts, Gus — or any items belonging to him — have not been located.

Detective Superintendent Fielke said he would not rule out further searches “if we do get new information”.

Darren Fielke with a map of Adelaide, comparing the search area for Gus Lamont at Oak Park Station with much of the city’s inner suburbs. (ABC News)

While police have said they remain committed to finding Gus, Dr Whitehead described their efforts so far as a “textbook search”.

“They’ve done the areas of highest probability first, they’ve searched around the homestead and worked their way outwards, they’ve done the mine shafts and all those sort of things,” he said.

“I don’t think they could have done anything more as far as searching goes.

“The search now has probably gone beyond the walking-on-the-ground sort of search, it’s going to be now an intel-driven search.”