A cadaver dog was brought from interstate as new locations were searched this week at the Oak Park Station homestead in South Australia's Mid North where the boy was last seen on September 27.
Police Commissioner Grant Stevens on Wednesday played down the possibility of an imminent arrest in the case.
"I haven't been briefed on the potential for that outcome but given the complexities around this particular investigation, it is a fair assumption that we will be working on the disappearance of Gus for some time to come yet."
Adjoining properties, including the national park, "will in all likelihood" be a part of investigations, he said.
"We'll use every resource available to us if it will contribute to solving the disappearance of Gus Lamont," Mr Stevens said.
"I think it's reasonably foreseeable that we will be visiting Oak Park quite frequently over the coming months as we continue our investigation as well as visiting surrounding locations in the vicinity of the residence."
On February 5, police declared Gus's disappearance a major crime and said someone living at the remote station was a suspect in the case and his likely death.
They confirmed the boy's grandparents, his mother and his younger brother were at the property at the time he disappeared but emphasised his parents were not suspects.
The latest police search by Task Force Horizon officers this week covered numerous buildings and structures at the station and at several locations adjoining the property.
Officers searched old mine shafts and inspected an outhouse with fresh cement and a water tank at a neighbouring property.
A police helicopter assisted along with the cadaver dog but no evidence was located.
On Monday, detectives investigating the disappearance arrested a 75-year-old from Grampus and charged them with firearm offences, but said the charges were unrelated to the investigation.
Oak Park Station is within the boundary of Grampus, a locality in SA's Mid North.
Police would not release the name of the charged person, citing privacy laws.
The person was bailed to appear in the Peterborough Magistrates Court on May 6.
Gus's grandparents Josie and Shannon Murray released a brief statement via their lawyers saying they were "absolutely devastated" by the police statements about someone at the station being a suspect.
Investigators searched the station homestead on January 14 and 15, seizing items including a vehicle, a motorcycle and electronic devices for forensic testing.
Gus's disappearance sparked intensive searches spanning almost 500 square kilometres and involving hundreds of police and volunteers as well as aerial support and mounted units.
Police have been to the station at least nine times since Gus was reported missing.
24°C