Australian authorities have ended the operation for a four-year-old who has been missing in the wilderness for nearly three weeks, after fresh efforts proved unsuccessful to locate any evidence of the youngster.
The child was last seen playing near his residence on a isolated sheep station in the vicinity of Yunta, about 300km from Adelaide, on 27 September.
His family member left him alone for about thirty minutes before checking on him, only to find the child nowhere to be found, triggering one of the most extensive comprehensive searches in the region's history.
Authorities - who do not think there was criminal activity - say they will carry on looking into, but that the situation has become a "recovery mission".
Recently, authorities temporarily wound down the operation, only to resume it on recently alongside numerous Australian Defense Force members.
"Official Grant Stevens said authorities were searching a wider area based on new analyses from survivability and rescue specialists, rather than any recent developments."
On Friday, authorities stated that the latest hunt had not uncovered any traces of the child.
"The fact that the young boy is a small child, the terrain is extremely rugged, harsh and affected by unpredictable elements has made the mission difficult and more difficult for those participating," authorities said in a announcement.
About 470 sq km - an zone roughly double the size of a major city - has now been covered, and a 12-person unit established recently is projected to carry on examining. Officials have not discounted additional searches of the location in the time ahead.
The boy, who has been described as an explorative but quiet child, was spotted wearing a gray hat, light grey trousers, shoes and a blue long-sleeve shirt displaying a golden character design.
The incident has generated substantial concern across the nation, with pictures of the blond, wavy-haired child displayed throughout local media and discussion spreading widely online.
It caused authorities to request that members of the public cease phoning them with their "theories", and appeal for them to source details from reliable channels.
Authorities earlier this week said the boy's loved ones remain "stoic" despite the difficult circumstances.
"One can understand just how they are feeling... without having clarity as to exactly where their child is and what's occurred to him. This would be devastating for all family," Spokesperson Stevens said.
Via a spokesperson, the family family has earlier said they are "overwhelmed" by the child's disappearance.
"This has come as a trauma to our household and acquaintances, and we are finding it difficult to comprehend what has happened," Bill Harbison said.
"Their son's absence is experienced in each family member, and we long for him exceeding words can express."