A volunteer who spent days on the search for a four-year-old boy who went missing on an Outback sheep station in South Australia believes he’s not even there.

Jason O’Connell, who was an SES member for 11 years, and his partner Jen covered more than 1,200km as part of the team looking for August ‘Gus’ Lamont on the youngster’s family farm about 40km south of Yunta.

Despite scouring the surrounding red desert day and night for more than 90 hours, searchers found no sign of the boy beyond a dubious sighting of a single footprint.

‘Jen and I were the only ones searching nights, apart from Monday night the father joined us, and we would head home when main search crews arrived through the day,’ he wrote on social media.

He explained he and his partner took the nights in case the boy was remaining still through the day ‘because of the heat or flies’ and moving at night.

They shone strong lights over the flat, barren landscape and also listened for foxes and kept a lookout for ‘birds of prey’ circling overhead but found ‘nothing’.

‘I personally am very doubtful he is on the property,’ Mr O’Connell said.

Gus was last seen playing in a mound of dirt near his grandparent’s homestead about 5pm on Saturday, September 27.

+6
View gallery

Jason O’Connell and his partner Jen (above) spent 90 hours searching for missing Gus Lamont

+6
View gallery

August ‘Gus’ Lamont was last seen on Saturday, September 27 at his grandparent’s property about 40km south of Yunta

+6
View gallery

Dozens of police, SES, army personnel and volunteers scoured the outback property

He had vanished by the time his grandmother went to call him in some 30 minutes later.

Hundreds of people scoured the surrounding area in the intervening days, including police, SES volunteers and members of the Australian Defence Force.

The boy had been wearing a grey broad-brimmed hat, a distinctive blue long-sleeved shirt with a Minion picture from the movie Despicable Me on the front, with light grey pants and boots.

But despite their best efforts, the only trace of Gus found was a footprint discovered about 500 metres from the homestead – and police have since cast doubt on that.

Local tracker Aaron Stuart told the media it was unusual to find one footprint as you would usually find ‘tracks’.

On Thursday, Yorke Mid North Superintendent Mark Syrus admitted the odds of survival were fading fast without food, water or shelter.

‘A four-year-old doesn’t disappear into thin air; he has to be somewhere,’ Supt Syrus said. ‘Hopefully he’s hanging in there alive … [but] it’s a long time to be out in the elements.

‘We always believe Gus is a tough little country lad. He may be curled up under a bush somewhere, and we’re determined to find him.’

+6
View gallery

Gus was last seen at his grandparents’ remote sheep station (pictured)

Police threw everything at the search for Gus, including specialist divers to check water tanks and dams, infrared cameras, dogs, ATVs, and drones.

But all that effort drew to an end on Friday when searchers packed up their gear and left the property.

Now the only sign that remains of the tragedy is a few forgotten knots of police tape tied on the station’s gates.

‘We’ve all been hoping for a miracle, but that miracle has not eventuated,’ Assistant Commissioner Ian Parrott said on on Friday.

‘At this point, no trace of Gus has been located. No tangible pieces of evidence, such as footprints, a hat or clothing, have been located to identify any direction of travel to assist searchers.

‘Despite our best efforts, we have not been able to locate him, and, unfortunately, we are now having to scale back this search for Gus.’

Police have handed the investigation over to the missing persons section after admitting the rescue mission had likely become one of recovery.

‘The investigation will now be managed by the missing persons investigation section,’ South Australia Police said in a statement.

+6
View gallery

Dams on the property were also searched but there has been no trace of the boy

+6
View gallery

A footprint that police said might have been left by Gus was found, but just the one

‘This is where all long-term cases such as this are managed and investigated, and is standard practice.’

Police do not believe a third party took Gus due to the remote nature of the homestead, which sits more than 25km from the highway.

Gus’ family have described the four-year-old as a shy but adventurous child. While he is known to be a good walker, he has never previously left his family property.

On Saturday, Leave A Light on Inc called on South Australians to leave their front door porch lights on so Gus could ‘find his way home’.

Investigations are ongoing.