Walter Kirn’s novels “Thumbsucker” and “Up in the Air” were adapted for the screen, but his latest work, “Blood Will Out,” faces a few Hollywood hurdles, even though the nonfiction piece tells a stranger-than-truth story that seems meant for the movies.

Even better, Kirn plays a co-starring role in the book, which charts how he was drawn into the orbit of the master con man who called himself Clark Rockefeller. But it’s been three weeks since publication, and CAA, which took the tome out to studios, still has no takers.

The problem? Its notorious subject: Rockefeller (real name: Christian Gerhartsreiter, a German native), who was convicted last year of a 1985 murder in San Marino, Calif., and posed at various times as a USC film student, a Rockefeller heir and the brother of Cameron Crowe. He was unmasked in 2008, when he kidnapped his own daughter in Boston.

The story is so fascinating, it’s already on Hollywood’s radar. Fox Searchlight acquired Mark Seal’s “The Man in the Rockefeller Suit” in 2011, with Walter Salles attached to direct. And several studio execs told Variety that the story was perhaps too familiar to audiences from the 2010 Lifetime TV movie “Who Is Clark Rockefeller?”

Says a Kirn rep: “I think there is a concern about whether the Searchlight film creates such an awareness of Rockefeller that it would raise the question if there is a need or appetite for another film.”

Insiders say the Searchlight script is too far along to combine the projects. But the difference between the books could work in Kirn’s favor, since “Blood Will Out” humanizes Rockefeller somewhat with the story of an unlikely friendship spawned from both men’s vulnerabilities.

(pictured, Walter Kirn at left, Christian Gerhartsreiter at right)