A man and woman who went missing whilst camping almost three months ago are suspected to have met with foul play, say police. Appearing on A Current Affair on Monday, Detective Inspector Andrew Stamper said he believes that a third party is involved in the disappearance.

Russell Hill, 74, and Carol Clay, 73, have not been seen or heard from since March 20 after the companions seemingly vanished without a trace while camping in Victoria’s Wonnangatta Valley. Hill, who has been married to wife Robyn for 50 years, and Clay were last heard from one day after they set off on their trip.

Russell set off from his Drouin home on March 19 and picked up Carol from her unit in Pakenham. The pair, who reportedly went away together regularly, travelled to Wonnangatta Valley, which is around six hours away from Melbourne. Hill made contact with his wife using a high frequency radio on March 20, however that is the last time that anyone heard from either of them. One week later, on March 27, a group of campers discovered the missing pair’s burnt-out campsite and the ongoing police investigation was launched.

Initial theories included the suggestion that the companions may have staged their own disappearance to begin a new life together, however Stamper believes there was “no reason for them to do that”. While alleged sightings of people matching the couple’s description have also been discredited by police.

“We would have found them by now if they were still up there,” Stamper, who leads Victoria Police’s Missing Persons Squad, told A Current Affair. “The strongest theory is that it is something that’s happened in the valley that has escalated and resulting in something bad happening to them.”

So far Victoria Police have spent 30 full days searching the valley, however they are yet to find any trace of either Russell or Carol. Police are also searching for a drone that belonged to Russell, which was also missing from their burnt-out campsite.

“We want to identify and eliminate anyone that was in the valley at that time. We’ve heard from very few people, I have to say it’s a bit disappointing,” Stamper added.

The new comments come almost two months after Russell’s wife told Daily Mail Australia that she does not believe her missing husband is likely to be found alive. She told the news outlet: “I don’t think that he will still be alive.”

Robyn’s comments come after the pair’s mysterious disappearance featured on Tuesday night’s episode of A Current Affair, with friends of Carol and Russell telling the Channel Nine program they believe that something has “gone awry”.

“She would never not communicate with her family,” Clay’s longtime friend Dorothy Coombe told reporter Sam Cucchiara. “Something clearly has gone awry. We know that something has gone awry.”

Victoria Police plan to continue searching the valley for as long as weather permits, with snow beginning to fall on the mountains.