Brian Laundrie Alleged Sighting on Appalachian Trail, Hiker Claims

Brian Laundrie is alive and on the run ... at least according to a Florida man who insists he came face-to-face with Gabby Petito's fiance.

Dennis Davis claims he was hiking on the Appalachian Trail Saturday when says he saw a dazed man on a deserted road ... right at the border between Tennessee and North Carolina. Davis says the man pulled his car up to his and asked for directions to California, but he did not want to take the Interstate ... he wanted to use back roads.

Davis says one of Dog the Bounty Hunter's daughters sent him audio of Laundrie's voice and says it was definitely a match, adding "There is no doubt in my mind I spoke to Brian Laundrie, none whatsoever" ... this according to the New York Post.

Davis went on to tell the Post Laundrie said, "Man, I'm lost ... me and my girlfriend got in a fight but she called me, told me she loves me, and I have to get to California to see her."

He says Laundrie was driving a light-colored pickup truck, like a Ford F-150 and was wearing a bandana.