Where is Gus Lamont? Mystery shrouds disappearance of four-year-old boy; family member 'a suspect'

The South Australian police have declared the disappearance of four-year-old Gus Lamont a 'major crime', revealing that a family member is a suspect in their investigation. 

Lamont went missing in September last year from the Oak Park sheep station in Yunta, north of Adelaide. A massive search has been launched by the police in the area to locate the missing boy. 

In a major development in the case, the police on Thursday said that a family member, who lived at the same property as the boy, had become a person of interest in the investigation. 

The inconsistencies in the family member's statements from the first time made the police suspect. 

Detective Superintendent Darren Fielke said that as a result of these inconsistencies, a person who resides at Oak Park Station has withdrawn their support for the police and is no longer cooperating with us. 

He also added that the parents are not suspects in Lamont's disappearance. 

 "We’re all focused and determined to locate Gus and return him to his parents. Nothing is off the table as we work towards that outcome," he said. 

The search for Gus has so far covered 95 square kilometres, including six mine shafts near the property. Along with the police officers, SES, the Australian Defence Force, an Indigenous tracker, aircraft and community volunteers joined the search team. 

The search in the scrubland was launched by the police on the assumption that Lamont had walked off from the Oak Park Station and got lost. 

"The other two investigation options are focused on Gus being abducted from the Oak Park Station or whether someone known to him was involved in his disappearance and suspected death," he said.