Police have taken two shovels into evidence in their search for missing Victorian campers Russell Hill and Carol Clay as detectives continue to believe other parties were involved in their disappearance.
Investigators widened the search area today to include Mount Hotham after the elderly couple mysteriously disappeared more than a year ago.
Missing Person Squad detectives and Search and Rescue officers began combing the area near the Great Alpine Road from 9am to pursue any clues.
UNDER INVESTIGATION: The mystery disappearance of Russell Hill and Carol Clay
Missing Persons Squad Detective Acting Inspector Tony Combridge said it was not clear how significant the discovery of the shovels was.
"At this stage I'm aware of the discovery, as to the relevance or its importance to the investigation, that is still to be determined."
The shovels will be assessed by investigators.
Police are considering all possibilities with regard to the mysterious disappearance of the pair.
"I think the most likely scenario is that there are other parties involved in this," Detective Acting Inspector Combridge said.
He said the reason for investigators turning their focus to Mount Hotham came from multiple sources.
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"The accrual of that information when put together as part of a bigger picture has helped us make the decision this might be a high-value area for us."
Detective Acting Inspector Combridge also said there were "no actual suspects at the moment" but an "enormous" amount of information had been received.
He added police wanted answers for the families of Ms Clay and Mr Hill.
"To be honest we don't know what we're going to find until we've searched it," he said.
"The area is of interest to us because of information we've uncovered.
"We want to find some answers."
The terrain at Mount Hotham is particularly challenging for search and rescue teams.
"There are parts of that bush that have probably never been walked on by humans," Detective Acting Inspector Combridge said.
"Some of this bush is so thick that we might not find what we're looking for … but it won't be for want of trying."
The last known contact with the pair was on March 20 last year via HF radio when Mr Hill stated he was at Wonnangatta Valley in the Victorian Alps.
Police believe Mr Hill left his Drouin home on March 19 last year and picked up Ms Clay from her home in Pakenham in his white Toyota Landcruiser.
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The pair then travelled via Licola, spending a night camping at Howitt High Plains, before heading into Wonnangatta Valley on March 20.
Campers found Mr Hill's vehicle with signs of minor fire damage at their campsite, which was destroyed by fire, near the Dry River Creek Track on March 21, prompting fears of foul play.
Detectives and specialist police have conducted numerous searches of the Wonnangatta Valley area over the past 12 months, however, the missing couple has never been found.
Cadaver dogs were recruited from NSW to assist in the search in the valley on April 4.
They are not being used as part of the Mount Hotham investigation.
Police have made repeated appeals to the public for anyone who was in areas of interest at the time to come forward.
Detectives have established Mr Hill was camping alone with his Landcruiser in the area of King Billy and Bluff Track, between March 11 and 13.
An older person or pair was later sighted at the Black Snake Creek, Eaglevale River crossing and the Ollies Jump area between March 22 and 23, however, police have never been able to determine if it was the missing campers.
"Detectives call for anyone in this area, any older couple who may be these persons, to also come forward."
Anyone who was in the area of Howitt Plains and Zeka Spur Track on March 19 or 20, the Wonnangatta Valley and Wonnangatta Station between March 20 and 24 who has not yet made contact with police, are also urged to come forward.
Police have also been looking for the person or persons in a white dual cab, four-wheel-drive utility ute seen at the time of their disappearance near the Wonnangatta River.
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Today Detective Acting Inspector Combridge said detectives were still making inquiries about the car and had "an enormous amount of information come in".
Police have extended the investigative team working on that line of inquiry.
The search will go throughout the day and is likely to continue tomorrow.
Anyone who sights Mr Hill or Ms Clay is urged to contact triple-zero immediately.
People with any other information regarding the couple's disappearance or who have any CCTV or dashcam footage is urged to contact Crime Stoppers on 1800 333 000.
