Forum:KB:Vader's helmet in the hands of Kylo Ren

Is there any detailed explanation for how Vader's helmet ends up in Kylo Ren's hands?

Questions and theories.. 1. According to the article on Anakin's funeral, "Vader's helmet was scavenged from his funeral pyre in the aftermath of the Battle of Endor", but it doesn't say by whom or when, or list a source. 2. According to "Star Wars in 100 Scenes", the pyre left behind "only ashes and small pieces of plastoid and metal", which in the "Force Awakens Visual Dictionary" includes his helmet. But i guess that's just changing the canon.

Theory A: Someone saw the funeral pyre, waited, and took the helmet when Luke left. An unseen watcher? Who? And would Luke not be able to sense the presence of him/her/it?

Theory B: Luke told someone the location of the pyre. Why? Especially since he wanted the funeral pyre to be kept secret from others (who would rejoice at the site), according to Disney's own canon addition "Return of the Jedi: Beware the Power of the Dark Side!."