As the search for a four-year-old boy who vanished from his grandparents’ Outback station enters its sixth day, hopes are beginning to fade he will be found alive.

A small, solitary footprint in the red dust, discovered on Tuesday amid the frantic search, is so far the only sign police have found of August ‘Gus’ Lamont.

Gus went missing from his grandparents’ remote homestead 40 kilometres south of Yunta, South Australia, on Saturday.

Conspiracy theorists have suggested the boy – last seen wearing a blue Minions long-sleeved T-shirt and a grey broad-brimmed hat – may have been abducted.

Police have been quick to refute the theory, instead focusing their search area within the radius of Oak Park station, where Gus vanished at about 5pm on Saturday.

In an exclusive interview with Daily Mail, a local from the town who has been living on the land for several generations concurred with the cops – and shared a frightening new theory about Gus’ possible fate.

The source said it’s highly unlikely a boy so small could have wandered the 40km to the Barrier Highway – a notorious, a 1000km desolate stretch of Outback road that connects South Australia to New South Wales, mostly frequented by lonely truckies.

‘If he made the highway, I’d hate to think who picked him up,’ said the source.

Police have swarmed the Outback station where four-year-old Gus vanished from on Saturday

Police have swarmed the Outback station where four-year-old Gus vanished from on Saturday

The child is thought to have wandered off while playing outside his grandparents' home

The child is thought to have wandered off while playing outside his grandparents’ home

Police have not released an image of Gus, but said he was wearing a blue Minions shirt

Police have not released an image of Gus, but said he was wearing a blue Minions shirt

However, he said residents of Yunta – a dusty dot on the map with two operational petrol stations, a post office and a pub with a population of just 60 – feel it’s far more likely Gus may have suffered another, equally grim, fate.

‘I would be more worried about the unmarked wells and mines he may have fallen into,’ he said. ‘That’s the talk [among locals].’

The state’s north-east pastoral district is dotted with mines and wells from a bygone era well over 100 years ago – and many of the region’s station owners are still stumbling across them to this day.

They were used as water sources for livestock and for those ‘chasing the gold dream’ back in the day, according to our source.

Many of these sinister holes are invisible to an adult’s naked eye – much less a meandering child’s.

Daily Mail’s source, who wished to remain anonymous, owns more than 30,000 acres of land that has been in his family for multiple generations, and is still stumbling across disused shafts and wells.

‘Most aren’t on any maps. If [Gus’ grandparents] have owned that property for a while, they should know where they are – although I’m still finding new spots on my property,’ he said.

The source shared a picture of one of the mines he had recently discovered, which shows why they are so difficult to see.

A local has shared an image of an abandoned well from years gone by which dot the region

A local has shared an image of an abandoned well from years gone by which dot the region

Police released an image of a solitary footprint in the dirt they believe may be Gus'

Police released an image of a solitary footprint in the dirt they believe may be Gus’

‘Most have different-coloured material around them from being dug out, but some are flush with the ground and have overgrowth all around them,’ he said.

‘Some are easy to see, some definitely not… but hopefully [Gus] is just lost… and not perished.’

Police do not believe Gus has been taken, as the only people who would travel on the nearby road are station owners.

‘The property is very isolated. You have to go through six gates to actually get to the station,’ Superintendent Mark Syrus said.

‘We’re focusing our efforts that he’s wandered off from the front yard.’

The specialist tracker spent all day Wednesday scouring for more footprints.

‘He covered a lot of ground but, unfortunately, just from that one track, he couldn’t find any indication of any other tracks in the area, which he said was unusual,’ Supt Syrus said.

Police continue to search a 3km radius from Gus’s last known whereabouts.

SA Police superintendent Mark Syrus said the search may turn into a recovery phase

SA Police superintendent Mark Syrus said the search may turn into a recovery phase

Police divers searched dams in the early days of their frantic hunt for the missing boy

Police divers searched dams in the early days of their frantic hunt for the missing boy

The Barrier Highway near Yunta is a desolate Outback road frequented by truckies

The Barrier Highway near Yunta is a desolate Outback road frequented by truckies

Yunta is a dusty dot on the South Australian map with a population of just 60

Yunta is a dusty dot on the South Australian map with a population of just 60

‘Yesterday afternoon, we had another review of our search and we’ve actually gone back to the property and searched it now for the third time, just in case he’s secreted or hiding somewhere around the property,’ Supt Syrus said.

‘Unfortunately nothing turned up.

‘So today, we’re continuing the search around the area and hopefully we’ll find a clue, a hat or something that might give us an idea of which direction he travelled in.’

This comes as police appeared to resign themselves to the search moving into a ‘recovery’ phase, as hopes fade Gus will be found alive.

‘Gus has been now missing for now into the fifth day, 84 hours, and a young boy without food, water, shelter for that period of time – it’s going to be pretty tough on that little lad,’ Supt Syrus said on Wednesday.

‘We’re preparing the family that we may be moving from a search effort to a recovery.’

On Thursday, Australian Defence Force personnel joined the hunt, which also includes a tracker with knowledge of the region.