Missing three-year-old William Tyrell could not have survived alone in the bush if he had wandered off alone from his grandmother's house on the NSW mid north coast last week, survival experts have told police.
As crews begin to scour the area around Kendall for a sixth day, they have come to the grim realisation that the search-and-rescue mission that began on Friday morning, and which has drawn hundreds of people to the tiny community, has most likely turned into a recovery operation.
Superintendent Paul Fehon, the commander of Strike Force Rosann that is investigating the boy's disappearance, said police still had no idea whether William, who was last seen wearing his favourite Spider-Man costume, had wandered off from the front yard of his grandmother's house on Benaroon Drive on his own, or whether "other forms of human intervention are involved".
But if he had wandered away, the likelihood of the boy surviving on his own in the thick bushland surrounding the property was non-existent, Superintendent Fehon said.
"As days go on, people are out there and trying to come to terms with survival in the bush," he said.
"Experts have advised us they can not substantiate that, at this point in time, survival could exist.
"Nevertheless, they [the search crews] are continuing. They want to assist the family in being able to locate young William and to at least bring them back something that they're desperately seeking."
Superintendent Fehon said William's family were under immense pressure, and were feeling numb following the boy's disappearance.
"They are very grateful of all the search efforts of everyone that's out here ... in regards to the efforts of trying to bring young William back," he said.
Fairfax Media believes that one of line of inquiry police are following is that a man asked staff in a local shop for directions to Benaroon Drive on Friday, before William went missing.
But Superintendent Fehon would not comment on that part of the investigation.
"We're grateful of all the information that's been provided to us at this point in time and we are following up on all those leads of information," he said.
"We need to go through that information, collate it and analyse it and we need to substantiate or discount that information that's provided to us."
Hundreds of SES, RFS and local volunteers scoured thick bushland on Tuesday and searched nearby dams and waterways for a second time, but there has been no trace of the boy.
Sniffer dogs and cadaver dogs found no scent in the yard, fuelling fears he may have been abducted.
The Sex Crimes Squad and investigators with expertise in unexplained disappearances of young children joined a team of 30 investigators on Tuesday.
Police are examining possible sightings from as far away as Casino.
Superintendent Fehon said searchers on trail bikes and in four-wheel-drives would join the search on Wednesday.
Anyone with information about William's disappearance has been urged to contact Crime Stoppers on 1800 333 000.
- with Rachel Olding
