Taskforce launched as search for Gus expands in SA's mid-north

Police have launched a taskforce into the disappearance of missing four-year-old boy Gus on his family's station in South Australia's mid-north.

SA Police Commissioner Grant Stevens this morning announced the creation of Taskfoce Horizon, which he said comprised of 12 people including "a range of specialists who will continue to analyse information, assess opportunities for further searches on the property and investigate all of the circumstances that possibly might have occurred that's resulted in Gus going missing".

He said the a renewed search starting on the property today and involving the Australian Defence Force (ADF) was "not based on new information" and there was " nothing to suggest foul play".

"There is no evidence to suggest any other circumstances that might have resulted in Gus not being located but we also have an obligation to consider all possibilities and that's part of our work going forward - to make sure nothing is left unaddressed," the commissioner said.

"Our focus is largely on an exhaustive search of the property, on the basis that Gus has wandered off, and we're hopeful that we can find him and return him to his family."

Commissioner Stevens said police continued to work with Gus's family who were grappling with unknowns about his disappearance.

"I would describe them as stoic, but you can imagine just how they are feeling without having Gus and without having answers as to where Gus is and what's happened to him," Commissioner Stevens said.

"This would be traumatic for any family.

"The family continue to cooperate with SA Police and we are grateful for that cooperation and we are doing what we can to support the family while we are conduct our investigations."

The original search covered an area the commissioner said was 100 times bigger than Adelaide's CBD - or about 470,000 square kilometres.

He said the new taskforce is coordinating and will continually reassess the renewed search effort.

"We are dedicated to making sure we do everything we possibly can to bring Gus back to his family," Commissioner Stevens said.

Premier Peter Malinauskas said he had been briefed on the situation, and the government had not been asked for additional resources.

"It's a new effort," he said.

"I'm confident police are treating this will all the seriousness and dedication it deserves."

Police have resumed the search today at the family's isolated and undulating sheep grazing station, about 350 kilometres north of Adelaide.

They said the search would "concentrate on an expanded area outside the zone already searched extensively" in the days after Gus vanished on Saturday, September 27.

He was last seen playing about 5pm on a mound of dirt outside the homestead on the property, which spans about 6000 hectares and is located about 43km south of Yunta.

Gus's family contacted authorities about three hours later.

Dozens of police, including major crime detectives and SES volunteers have arrived at the property today, along with about 80 ADF personnel who congregated before rolling out to various locations across the vast station.

Members of the media have been escorted to a staging area.

Police said they expected to remain at the property until the end of the week.

ABC reporter Genevieve Blandin de Chalain arrived at the property this morning, which she said appeared "incredibly dry" with "challenging" terrain.

"From afar the ground looks deceivingly flat but it is uneven and covered with dry shrubbery and trees," she said.

"All the vehicles have had to battle difficult obstacles of sandy roads and unreliable dirt tracks.

"The drive into the staging area on the property is almost one hour from the Yunta township itself and completely on unsealed road."

She said vehicles picking up dust had created poor visibility and made it difficult for the convoy of vehicles to keep track of each other.

"We came across ADF personnel on our way into the staging area and asked them for directions but they'd been separated from their group as well due to the poor visibility caused by the vehicles picking up dust," she said.

Initial searches for the boy involved police, SES, the ADF, a tracker and community volunteers who scoured the ground for clues.

Only a single footprint with a "very similar boot pattern to what Gus was wearing when he went missing" was found during the initial search efforts.

The extensive aerial, land and water search also involved a police helicopter, drones, water operations teams and police cadets.

Police previously said they suspected that Gus had "wandered away from the property", and said his family had described the boy as a "quiet" but "pretty adventurous" child.

In a statement released yesterday, police said there had been "regular and close engagement" with Gus's family, who were "continuing to assist with the investigation".

After Gus's disappearance, family friend Bill Harbison delivered a statement on behalf of the boy's family.

He said the family was "devastated" and that they missed him "more than words can express".

"This has come as a shock to our family and friends, and we are struggling to comprehend what has happened," he said.

Just a day later, police said the search had moved into a recovery phase.

On Friday, October 3, police revealed they were scaling back the search, which they said was one of state's "most intensive" in recent times.

At the time, police said their presence at the property would be reduced, but an investigation would continue.

"Whilst we have all been hoping for a miracle, that miracle has not eventuated," Assistant Commissioner Ian Parrott said at the time.

"Unfortunately, at no point has there been any significant evidence to … give us any clues to where he may have gone."

Later, police said they conducted further searches of the family's property "using a special drone with infrared capabilities".

During the search, police said their phone lines had been "inundated" with unwelcome speculation about the fate of Gus, while fake images and information has circulated on social media.

When he vanished, Gus was wearing a grey sun hat, light grey long pants, boots and a blue long-sleeve T-shirt featuring a yellow Minion character.

- ABC