Board Thread:Skyrim/@comment-100.36.68.44-20190101175954/@comment-26213507-20190102001131

You can try selling to a fence, or putting it in a container and letting a follower grab it, although since it's probably listed as a quest item, that won't work. I'd suggest that you reload a save from before entering High Gate Ruins, and then enter/complete the dungeon again. If it is still marked as stolen, reload again and wait ~10 days before coming back.