It was my understanding that L. Ron Hubbard began as a science fiction writer, at one point plagiarizing another's works in a backwards sort of way, that is reversing the story item by item until he worked up a complete "opposite" book.
Then the story goes that he had some sort of paranoid psychotic break and began believing that the FBI was following him. Supposedly through the Freedom of Information Act, it was revealed that the FBI had no interest in Hubbard at all. Apparently, the FBI recognized that Hubbard had some serious mental health issues. Hubbard's "file" supposedly mostly contains his accusatory letters to the FBI regarding his belief that they were following him.
There are conflicting stories about Hubbard's death. Some ex-cult members claim that Hubbard died under mysterious circumstances related to members within the Church of Scientology.
Based upon the Church of Scientology's continual dissemination of propagandizing yet factually incorrect press releases, upon their aggressive and some say deadly cult indoctrination, it would come as no surprise if their affiliation is proven to be even more nefarious, as you have suggested.