Search continues for missing Vic pair

A search is underway to find a man and woman missing in Victoria's high country for more than 10 days.

Russell Hill, 74, left his Drouin home on March 19 for a camping trip across several sites along the Dargo River in Victoria's northeast.

Carol Clay, 73, told friends she was heading away for a few days and expected to be home by March 29.

Neither has been heard from since March 20, when Mr Hill made radio contact from a remote station in the alps.

During the call, he said he was having radio transmission issues.

Search efforts on Tuesday will focus on the camping ground where Mr Hill's car was found with signs of minor fire damage near the Dry River Creek track at Billabong on Friday.

Police believe Ms Clay is travelling with Mr Hill, as some of her belongings were found in his car.

Police, supported by air surveillance and the dog squad are searching, helped by members of the State Emergency Service, Parks Victoria and the Mountain Cattlemen's Association of Victoria.

Colleagues are concerned for Ms Clay, a past Victorian Country Women's Association president.

"She is held in great esteem by members and colleagues and is a great mentor," deputy state president Pam Mawson told AAP.

"I did know she went camping. We are all very concerned and keep watching all the news."

Inspector Craig Gaffee, who is leading the search, told reporters on Monday it remained a "mystery" why the pair had gone missing from their campsite.

"The campsite itself and vehicle are really well equipped," he said, urging anyone who had been in that Billabong and Wonnangatta Track to come forward.