Nancy Guthrie Development, Bones Located Near Home Not Connected

Authorities have recovered what appears to be human remains in a desert 15 miles from Nancy Guthrie's home. The Pima County Sheriff says so far there's no indication the bones are connected to Guthrie, but we have a more definitive answer.

Law enforcement sources with direct knowledge tell TMZ, the bones were discovered in a "very remote" area of the desert ... only accessible by a long hike. One source said, "Our boots on the ground say the bones are definitively not Nancy Guthrie."

We're told the remains are "bleached white bones" which have been there for a long time. Bleached white bones occur when ultraviolet rays from the Sun break down the organic components of the bones, resulting in a loss of color and turning them white.

Our sources say there are still no leads in capturing Nancy's kidnappers or locating her remains.