Victoria Police have arrested a man in connection with the mystery disappearance of two campers in Victoria’s rugged high country more than 18 months ago.

Police said on Tuesday they had arrested a 55-year-old man from Caroline Springs, in Melbourne’s north-west.

He was being questioned on Tuesday morning.

Russell Hill, 74, and Carol Clay, 73, were last heard from on March 20, 2020 while camping in the Wonnangatta Valley.

Mr Hill left his Drouin home on March 19 and picked up Ms Clay from her home in Pakenham in his white Toyota LandCruiser.

He was last heard from on March 20 when he made a call via HF radio saying he was at Wonnangatta Valley in the Victorian Alps.

Ms Clay 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 fire-damaged car at their campsite, which was completely destroyed by fire, near Dry River Creek Track on March 21.

The pair have not been seen or heard from since.

Earlier in November, Victoria Police released details of a blue four-wheel-drive they said they believed could hold the key to solving the case.

They released images of the vehicle – believed to be a mid- to late-1990s model Nissan Patrol – taken by a safety camera in the area.

Witnesses had reported several sightings of the vehicle, with police yet to pin down the driver or exclude them as a person of interest.

Police said they believed Ms Clay and Mr Hill might have had an altercation with another camper at the campsite, possibly the driver of the blue 4WD.

At the time, leading investigator Detective Inspector Andrew Stamper said it could be the breakthrough police needed.

“We could be one phone call away from solving this,” he said.

On Tuesday, police said their investigation remained ongoing and more information would be released only when “operationally appropriate”.

-with AAP