Bookmark.
To me that seems to be the best bet, that he is a Polynesian (or his parents were), who may have had a small amount of negroid genetic background in him.
In the catechism he produced for the NOI, he mandated sacrifice of 4 whites for each each NOI member. He disappeared in the 1930’s and it was thought that he was sacrificed, himself, or that Elijah murdered him.