A crime scene has been established in Victoria's alpine region with police focusing their efforts on finding the remains of Russell Hill and Carol Clay, after a man was charged over their murder.
Airline pilot Glen Lynn, 55, will face Sale Magistrates' Court on Friday morning after being charged with two counts of murder.
Victoria Police Assistant Commissioner Bob Hill said detectives had identified a crime scene within the Great Alpine Region on Thursday morning, as he warned their investigation "is far from over".
"We've located a specific area and we will be establishing a search parameter in the coming days," he told reporters on Thursday night.
"We are hopeful that we will locate the remains of Mr Hill and Ms Clay... and provide closure to their families."
He declined to give the exact location of the crime scene, due to significant community and media interest.
"We are hopeful that we can establish our infrastructure and our search parameters and we don't want the community and other parts of the media to impact on that area at this point in time," he said.
He confirmed no one else was being sought for the murders and called for anyone with information, particularly on a blue trailer, to contact police.
The trailer, which was sold between March and July 2020, was attached to a blue four-wheel-drive, believed to be a mid-to-late-1990s Nissan Patrol.
"We believe the trailer was sold on Gumtree," he said.
Asst Comm Hill expressed his condolences to Mr Hill and Ms Clay's families, saying "the past 20 months has been an incredibly difficult time for them".
He said police had gone through an "exhaustive and complex criminal investigation" since the two campers disappeared in March last year.
"It is one of the most significant investigations we've undertaken in recent years," he said.
"There's been hundreds of people spoken to, hundreds of vehicles that have been eliminated, in excess of 1000 information reports are on the system.
"Investigators are relieved, but they appreciate there's more work to be done."
Mr Lynn, from Caroline Springs, was arrested by specialist police on Monday at a remote campsite in Arbuckle Junction, 280km northeast of Melbourne. His Nissan Patrol four-wheel-drive has been seized.
Asst Comm Hill said the arrest came after police adopted "unique investigative techniques" with support from specialist services.
Mr Hill and Ms Clay were last heard from on March 20, 2020 while camping in the Victorian Alps.
Mr Hill left his Drouin home on March 19 and picked up Ms Clay from her home in Pakenham in his white Toyota LandCruiser.
On March 20, Mr Hill - an experienced outdoorsman - made a call via high-frequency radio saying he was at Wonnangatta Valley.
Ms Clay, a former Victorian Country Women's Association president, told friends she was heading away and expected to return home on March 28 or 29.
Investigators were told the couple were camping together at Wonnangatta River near the Wonnangatta camping ground.
Campers found Mr Hill's car destroyed by fire at their campsite near Dry River Creek Track on March 21.
The pair have not been seen or heard from since and police believe they may have had an altercation with another camper.
Australian Associated Press