Perhaps the greatest literary hoax of recent years, the creation of a pseudonymous author called JT LeRoy was the subject of Jeff Feuerzeig’s documentary “Author: The JT LeRoy Story” a few years ago. That film, however, told the tale entirely from the perspective of Laura Albert, the San Francisco woman who invented JT—supposedly an androgynous, HIV-positive teen who’d been abandoned in California by his mother, a West Virginia truck-stop prostitute, and told his own story in captivatingly artsy prose—in the 1990s, publishing “his” books, “Sarah” and “The Heart is Deceitful Above All Things,” in 1999. The documentary was less investigation than apologia for the woman, whose deception had been unmasked in 2006. (She was later convicted of fraud for signing legal documents as LeRoy, but settled with the plaintiffs.)

By contrast the focus of Justin Kelly’s dramatization is Savannah Knoop, the young woman who impersonated JT in public appearances from 2001 on; the movie is based on Knoop’s 2007 memoir “Girl Boy Girl: How I Became JT LeRoy,” and Knoop, the sister of Albert’s partner Geoff, co-wrote the script.

The result is no less a partial account of the JT LeRoy affair than “Author” was, though most viewers will find it more enjoyable, largely because of the starry cast. It begins in medias res, so to speak, when Savannah (Kristen Stewart) is introduced to Laura (Laura Dern) by Geoff (Jim Sturgess). The books are already out and while Laura has up till then been handling contact duties herself—portraying LeRoy on the phone—she needs to find a way to present her creation in the flesh to press and public, and nineteen-year old Savannah looks as though she could fill the bill. Photo shoots pave the way, but before long she’s dressing as LeRoy for press conferences, book signings and other appearances; but she mostly keeps her contributions to a minimum as Albert, adopting the persona of “his” flamboyant British manager Speedie, handles the questions.

There’s an air of abandon to these scenes, as Albert and Knoop take on incredulous reporters and adoring fans, one played by Courtney Love (who was actually one of the celebrities who joined the LeRoy bandwagon). The jaunty score by Tim Kvasnosky, with lots of tooting pipes, emphasizes the feeling that the whole charade is innocent fun, though there’s an unsettling undercurrent in the impact that LeRoy, as well as the story he tells, has on many readers facing the same sorts of trials that he supposedly had.

Moreover, just as “Author” served as a means for Albert to justify what she’d done, so Kelly’s film allows Knoop to do likewise. Savannah is portrayed as a young woman struggling to find herself at a crucial moment in her development, a struggle that included questioning her sexuality. While she is acting the role of a young man, she also is a young woman developing a relationship with a nice young man named Sean (Kelvin Harrison Jr.).

But another possibility appears when Savannah and Laura travel to France and meet Eva (Diane Kruger), a European actress anxious to secure the rights to adapt a film from the LeRoy books. (The character is obviously a stand-in for Asia Argento, who would in fact direct a feature based on “The Heart Is Deceitful Above All Things.”) Savannah is drawn to her, though the actress is interested only in the texts, not their author in a sexual sense.

Savannah’s journey of self-discovery is really the center of this film—an interesting story, but less about the entire JT LeRoy saga than about Knoop, whose life was clearly altered by her role in it, not simply in terms of her part in what became a literary scandal, but how it was a catalyst to her self-understanding. Stewart manages to convey the sense of Savannah’s personal journey in the quietly nuanced, understated fashion familiar from her previous work. It’s a subtle performance, even when Savannah takes on the admittedly unusual character of LeRoy.

By contrast Dern offers a wildly flamboyant turn as Albert, portraying her as a master manipulator whose ability to ride roughshod over others to achieve her immediate purposes defined her character: Savannah is the introvert used by the over-the-top extrovert Albert to fulfill her dream. Of course, in the process of succeeding in making people believe in the reality of JT LeRoy through Knoop’s imposture, Albert also lessened her own control of the situation—which, the films suggests, was a real irritation for her.

Sturgess and Kruger add to the film’s gallery of peculiar characters with nice supporting turns, and the crew (cinematographer Bobby Bukowski, production designer Jean-Andre Carriere, costumer Avery Plewes, editor Aaron I. Butler) work to give the picture vitality, though despite their best efforts it can get sluggish at times. And that score can be irritating.

But despite the title, this film isn’t so much about JT LeRoy: it’s as much an apologia for Savannah Knoop’s role in the con as “Author” was for Laura Albert’s. On those terms, however, it’s a moderately enjoyable account of one of the most flagrant literary hoaxes of modern times, especially because of the performances.