B.C. Coroners Service will now take over to determine if the remains are human and if they belong to McKellar.
"The identification of the remains is a top priority for investigators," says Victoria police spokesman Bowen Osoko.
"Police have advised the McKellar family of the discovery. Once identified, the appropriate next-of-kin notifications will take place."
More than 90 detectives have spent several days combing through a large field and several homes on the 100-block of Goward Road in Saanich, B.C.
The 51-year-old was last seen near the 500-block of Dallas Road last summer, and was reported missing about three weeks later on Sept. 2, 2014.
Police say McKellar had been assaulted in the weeks prior to his disappearance, and a search of a property on the 1200-block of Burnside Road West led them to new evidence on Goward Road.
"We found some concerning blue barrels. They're like big, oil drum sized blue barrels. They were unlabelled and they had some concerning contents," said Victoria police spokesperson Mike Russell before the search started.
Anyone with information on McKellar's disappearance is being asked to call the Victoria Police Department's non-emergency line at 250-995-7654. Those wishing to remain anonymous can also contact Crime Stoppers at 1-800-222-TIPS or solvecrime.ca.