Advertised as a starring vehicle for Robert De Niro, "The Swap" is in fact a disreputable patchwork, consisting of remnants from "Sam's Song," an unreleased 1969 feature in which a very young and relatively unknown De Niro played one of the leads, plus hastily assembled recent footage calculated to provide the abandoned movie with a melodramatic framework.

The deception is inexcusable in every respect. The filmmakers hired to cover the tracks of "Sam's Song" appear more amateurish than their predecessors. The result of juxtaposing a new batch of misbegotten footage with an old batch of misbegotten footage is inevitably ludicrous and pathetic, a demonstration that two cinematic wrongs add up to a double-decker wrongie.

An entry in Leonard Maltin's "TV Movies" describes "Sam's Song" as a "dreary film about a film editor's weekend with friends on Long Island." A friend in New York recalls the movie being "premiered" on a local TV station sometime in the early '70s to the consternation of several of the self-respecting people involved, notably the director, Jordan Leondopoulos, who had been so embarrassed by the fiasco of "Sam's Song" that he abandoned filmmaking and returned to college to earn a doctorate in English literature.

The direction of "The Swap" is credited to the unfamiliar "John Shade," with additional scenes by the equally renowned "John C. Broderick." It's a fair bet that neither shooting party was ever permitted a retake. The level of craftsmanship may be gauged by a definitive Z-production highlight: We see a character obviously being shot during a struggle over a gun, but the sound of the fatal gunshot is nowhere to be heard.

It's impossible to tell from the remaining fragments what "Sam's Song" was meant to be about. One gathers that De Niro was cast as a dreamy movie freak of some kind. He's seen peering at a moviola in what may be his apartment or office or both. He's seen reading Andre Bazin's "What Is Cinema?" He's seen repeatedly falling down after shooting himself with an index finger during a whimsical play-dead sequence in slow motion, probably intended as a homage to Jean-Luc Godard's lovely but now obscure romantic thriller, "Band of Outsiders."

The original company obviously borrowed someone's yacht and Long Island mansion for scenic purposes, but the dramatic intentions of this material remain shrouded in mystery. It appears that the winsome, ineffable De Niro is attracted to Jennifer Warren, the wife of a patron who happens to be cheating on her with a blond starlet De Niro is also dallying with.

The additional footage is crudely manipulated to suggest that the De Niro character was a murder victim, whose death is avenged a decade later by his older brother, a paroled convict named Vito. Played by a pub-faced actor whose name is unknown to me (although "Jerry Mickey" appears to be the ideal name among the cast members credited with leading roles), Vito is shown grimly plodding around Los Angeles interrogating people who knew his kid brother, before finally liquidating the culprit.

The interview subjects include the deceived wife and amorous blond, now impersonated by different actresses. Since the movie keeps jumping back and forth from new footage to old footage, the casting changes are almost brazenly apparent.