A 55-year-old man has been charged with two counts of murder over the disappearance of Victorian campers Russell Hill and Carol Clay.
Victoria Police Assistant Commissioner Bob Hill is expected to give an update on the case at 7:15pm on Friday.
The Caroline Springs man has been in custody since being arrested on Monday night by specialist police at a remote campsite in Arbuckle Junction, 280km northeast of Melbourne.
His Nissan Patrol four-wheel-drive has been seized but police are yet to track down his trailer.
Earlier on Thursday, Victoria Police's top cop said detectives believed the silver-coloured trailer was sold last year between March and July.
Chief Commissioner Shane Patton appealed for anyone who bought one at that time matching the description to come forward, in an interview on Melbourne radio station 3AW.
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.
Multiple searches have been conducted in and around the Wonnangatta Valley, including with cadaver dogs.
Earlier this month, police released images of a blue four-wheel-drive, believed to be a mid-to-late-1990s Nissan Patrol, taken by a safety camera in the area at the time Mr Hill and Ms Clay went missing.
Witnesses reported a number of sightings of the vehicle, including near the campsite, with police yet to track down the driver or exclude them as a person of interest.
Police believe the pair may have had an altercation with another camper, possibly the driver of the blue 4WD.
It was towing a trailer and was heard performing a 20- to 30-point turn on a narrow track the night the pair vanished.
