Sinister theories have re-emerged that four-year-old Gus Lamont may have been abducted after cops failed to find any clues at the bottom of a dam.

Gus was last seen playing in a mound of dirt near his grandparents’ homestead on a sheep station 40km south of Yunta, in eastern South Australia, at about 5pm on September 27.

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

Police began searching the 60,000ha property shortly after Gus disappeared but found no sign of the little boy.

The extensive land and air search for Gus was scaled back from a rescue to recovery on October 3, just hours after a photo of Gus was released by the family.

Last week, South Australia Police released a statement, revealing the search for Gus would resume, with officers draining the dam on the family’s homestead on Friday to rule out the possibility Gus may have drowned.

No trace of the four-year-old was found.

With drowning ruled out, online speculation has exploded, with many refusing to believe the little boy simply wandered off.

‘They keep insisting he wandered off. I wish they’d look at other avenues,’ one wrote.

‘There are workers on those sheep farms. Where is their questioning? There’s more to this.’

Others echoed similar frustration.

A third suggested: ‘There’s no way a kid disappears into thin air with only one footprint on a property that size.’

Some believe foul play is the only explanation.

‘Someone has him,’ one wrote.

‘If an eagle or fox grabbed him, there would be signs.’

Another added: ‘This whole disappearance has been suspicious from the beginning. I’ve always thought he’s been taken. Why aren’t they looking in that direction?’

A few offered alternative theories.

‘I have this sickly feeling he’s fallen into a wombat burrow,’ one wrote.

But the overwhelming sentiment online remains one of unease and suspicion.

‘Someone has him. No one just evaporates without anyone knowing what happened.’

Many locals were holding out hope draining the dam would bring closure for the close knit community who have been left devastated by the loss of one of their own.

One resident who has lived in town for almost 30 years told Daily Mail locals were waiting with bated breath.

‘You don’t want him to be found like that but at the same time at least we’d know what’s happened,’ they said.

The little boy was last seen outside his grandparents’ house on September 27 at about 5pm.

He was under the care of his grandmother Shannon Murray while his mother Jessica and grandparent Josie tended to their herd of sheep 10km away.

Police stressed to date investigations had not uncovered ‘any evidence of foul play’.

Despite their best efforts, the only trace of Gus was a single footprint found about 500m from the homestead – which police have since cast doubt on.

However, police made the tough call to scale back the search based on scientific and professional advice on how long a four-year-old could survive alone in remote terrain in freezing overnight temperatures in the clothing Gus was last seen wearing.

Gus was last seen wearing a grey broad-brimmed hat, a blue long-sleeved shirt with a Minion picture from Despicable Me on the front, light grey pants, and boots.

South Australian Assistant Police Commissioner Ian Parrott said police believe Gus wandered off and was not taken, as the only people who travel on the nearby road are station owners.

‘Everything that we have found to date, every piece of information and evidence that we have explored to date, indicates that, as best as we know, Gus has wandered off from this property and we have not been able to locate him,’ Parrott said.

Anyone with information is urged to contact police.