The mystery surrounding the disappearance of a secret senior couple, Russell Hill and Carol Clay, who went missing from a remote Wonnangatta Valley campsite on March 20 last year, is about to be solved as detectives ruled out the possibility of the pair staging their disappearance.

The Victorian campers were last sighted at their campsite at Dry River Creek Rack, which was later on discovered to be burnt down.

Additionally, it was also discovered that Hill's Toyota Landcruiser was abandoned.

Detectives say that the possibility that the pair staged their disappearance is highly unlikely, as new reports suggest that a car was spotted near the campsite around the same time the pair disappeared.

The vehicle is a dark blue mid-1990s Nissan Patrol which had a trailer attached to it.

The new information led the investigation to shift its focus on the possibility of the couple getting murdered by a stranger after an altercation.

“Everything seems to point towards this being some sort of confrontation, which has started as an argument maybe,” Victoria Police Detective Inspector Andrew Stamper told 60 Minutes.

“But my belief is that the person that carried out this is probably just an ordinary member of the community, who’s operating in a normal job, but carrying this significant load on their mind.”

Stamper said that witnesses said that a vehicle attempted to leave the valley late on the night the couple disappeared, noting that the vehicle was forced to make a complicated turn back in the direction it came due to a closed gate.

Stamper revealed: “That same vehicle is also spotted on two cameras at the top of Mount Hotham, consistent with where a vehicle would exit the valley given the closure of the Myrtleford gate.”

“We understand that initially, given the confusion around COVID-19 and state-wide lockdowns that people may have been reluctant to come forward, or that someone may simply have missed our repeated appeals for information.”

Stamper also revealed that they discovered charred camping chairs, a burnt-out battery, and a bucket, that may possibly be used for Hill's gas canister, inside the campers' burnt-out tent, believing that these items were unlikely to be put by the couple themselves.

“It certainly builds that picture for us that potentially someone was trying to cover their tracks.”

The detective encouraged anyone who recognises the dark blue car or knows any more information to reach out to the police.

“If you are the driver of this blue Nissan Patrol, or you know who is, we would urge you to come forward – if nothing else, so we can eliminate you from our inquiries and move forward.

“Both families are still desperate for answers about what happened to Russell and Carol and why, and I know our investigators are doing all they can to try and get those answers for them.”