A footprint initially thought to be that of missing four-year-old August ‘Gus’ Lamont has been ruled out by police as they further scale back their massive search in South Australia’s unforgiving outback.

Gus was last seen by his grandmother in a blue Minions shirt playing outside on a mound of dirt at his family’s Oak Park Station homestead before he vanished around 5-5.30pm on Saturday, 27 September.

The alarm was raised and what ensued was “one of the largest, most intensive and most protracted searches ever undertaken” by South Australian Police, according to Assistant Commissioner Ian Parrott.

A small footprint found last Tuesday, just 500m from where Gus was last seen, sparked hope he might be found.

At the time, Superintendent Mark Syrus said authorities were “buoyed” by the find.

But that now appears to have been discounted with further investigation.

“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,” Commissioner Parrott said on Tuesday.

“We are confident that we have done all we can to locate Gus within the search area.

“Despite our very best efforts to find Gus we have determined that the search will be scaled back from this afternoon.”

After more than a week with no sign of Gus — described by his family as shy but adventurous — hopes for a miracle faded and the search, which covered 47,000ha, had turned to one of a recovery mission.

Now it is set to be further scaled back and handed over to the missing person investigation section.

Senior police spoke to Gus’ family on Tuesday to prepare them for the fact that he may not have survived due to the passage of time, his age and the nature of the terrain where he went missing.

Commissioner Parrott said that alongside the search, police had been undertaking the usual inquiries that happen “as a matter of course when a 4-year-old child goes missing”.

“We are investigating and looking to rule out every option at this stage.”

Commissioner Parrott said Gus’ disappearance had affected all involved in the search.

“The determination of every individual involved to find Gus has never wavered,” he said.

“Like every member of the community who has been following this sad event, they too have been very much affected by what has happened.

“They are all mothers, fathers or have young siblings and share the anguish and despair that Gus’ family have been going through since last Saturday night.”

The police update comes after a SES volunteer who helped with the search claimed there was “zero evidence” Gus was still on the sheep station.

Jason O’Connell combed through Oak Park Station with his wife Jen, telling The Advertiser, “it’s just wide, open land.”

“There’s really not much there, and with our lights I’m surprised because we just didn’t find anything,” the 50-year-old ex-SES volunteer said.

“He’s not on that property.”

Mr O’Connell said it’s incredibly rare to not find a single trace of a person who has gone missing.

“I just don’t get how (Gus) vanished like that,” he said.