Hubbard complained of a conspiracy, in a letter to the FBI dated May 14, 1951.
Details refer to some of the reports that are now posted online (at
www.meepthorp.com)
"Their first blast was the San Francisco papers, Sept 1950, quoting the publisher (of Book One) Ceppos being critical of me (he was a communist) followed by the LA papers, pushed then by the Sara Komkovadamanov (alias Northrup) 'divorce' actions, followed by attempted kidnapping of myself. Other details were pushed into it including murder of four and so on. This was a full complete covert operation. At the back of it was Miles Hollister (psychology student), Sara Komkovadamanov (housekeeper at the place nuclear physicist stayed near Caltech)..."
The other referenced deaths were Dr. Rowland Walker (Dianetics' first Medical Director), and an unnamed applicant who sought Dianetics auditing.
http://www.xenu.net/archive/FBI/fbi-110.html