“I Touched All Your Stuff” is a maddening, intriguing, shout-at-the-screen kind of documentary, seemingly wildly undisciplined yet rigorously (over)constructed — it’s the cinematic equivalent of the Pompidou Center, parading its structure all on the outside. The subject is convicted American drug smuggler Christopher Kirk, whose shaggy-dog tale of naivete and hopeless love so captivated Brazilian helmers Maira Buehler and Matias Mariani that they plunged into his story, only to discover that winnowing truth from fiction was impossible. Kirk is an exasperating protagonist, the voiceover is annoying and the amount of filler footage would jam up the Erie Canal, yet con men are intrinsically fascinating, suggesting fests could have a conversation-starter on their hands.

Apparently the directors initially thought of making a film about foreign jailbirds in Brazilian prisons: Then they met Kirk in the slammer and shifted focus after being won over by his winning, earnest manner. What really hooked them was his story about traveling to Colombia from Olympia, Wash., because he was tickled by a TV program on rampant hippopotami living in Pablo Escobar’s former compound (subject of 2010’s “Pablo’s Hippos”) — hence the docu’s Portuguese title, which translates to “The Private Life of Hippos.” Sometime later in “I Touched All Your Stuff,” Buehler says Kirk is a great storyteller, but it’s as if he’s distanced from his own story. Well, duh: The guy is a master inventor if not (very likely) a psychopath.

Kirk himself, dressed in the yellow top you’d find at a Sao Paulo big house, looks like butter wouldn’t melt in his mouth, especially when discussing the love of his life, referred to only as V. She was a half-Japanese, half-Colombian woman of mystery, and the more Kirk describes their relationship, the more any sane person will question his veracity. The directors were given access to Kirk’s hard drive, resulting in an overload of shots of thousands of file icons, with photos and songs (mostly by Joseph Arthur), though only one distant, fuzzy image of V.

It’s never clear when the directors cotton on to the fact that their subject is such a fabulist. If one goes chronologically, using the film’s chapter divisions, then only after about 75 minutes do any of the many friends and associates interviewed state that Kirk uses his honest face as a front, disguising his less-than-savory activities. Before then, the folks back home in Michigan and Washington speak of him in saintly terms as the original naif, gullible and uncorrupted. Apparently they didn’t know about his penchant for stories about con men and grifters.

Buehler and Mariani seem uninterested in asking probing questions (or even basic ones, like where was Kirk’s money coming from?), probably because they realized there was no way of separating truth from lies. It’s part of their bid for a multilayered approach, which deliberately uses directorial involvement as a way of reflecting on the limits of nonfiction filmmaking — a topical subject, given the skyrocketing number of docu-fictions in recent years.

Unfortunately, as if to concretize every identifiable statement, they overload “Stuff” with a barrage of footage with only tangential relevance: For example, when someone likens Kirk to Pinocchio, they insert scenes from “Pinocchio.” No point is made without similarly unnecessary illustrations, and these constant cuts form a major source of irritation. The English-lingo title derives from a bizarre story about a friend of Kirk’s who surprised him by wrapping his entire apartment, objects included, in aluminum foil.