After the release of K-PAX (2001), based on Gene Brewer's 1996 novel, "Southeast" director Eliseo Subiela sued Brewer, claiming plagiarism from this film. He lacked the funds to pursue his claim, and soon dropped the matter.
Persons interested in philosophy may recognize Rantes' basic position on ethics to be that of renown ethical philosopher Immanuel Kant. The ethical good is simply that which makes sense. Put that together with his stated mission, to figure out what is wrong with earth people before we get off this planet. The implication is that the earth, as a whole, is not sane.
Subiela wrote the script in a month.
Filmed at the Borda Hospital, a real mental institution located in Buenos Aires. Some patients appear as extras in the movie.