The "buried secret" that the Sci Fi Channel claims it uncovered about filmmaker M. Night Shyamalan is that there really is no secret.

The cable network, which has heavily promoted a three-hour documentary about Shyamalan, has admitted to lying about the show's content. Rather than an unauthorized expose about the "Signs" and "Sixth Sense" director, "The Buried Secret of M. Night Shyamalan" -- airing Sunday night (July 18) -- is instead a "part-fact and part-fiction" mockumentary, Sci Fi president Bonnie Hammer says.

"Night was part of the creation from the beginning," Hammer tells the AP. "Perhaps we might have taken the guerilla [marketing] campaign one step too far."

"Buried Secret" is tied to the release of Shyamalan's latest movie, "The Village." In publicizing the special Sci Fi claimed that filmmakers Nathaniel Kahn ("My Architect") and Callum Greene ("Lost in Translation") started out to do a standard making-of film, but as they started to dig into Shyamalan's life, the director cut off their access.

They plowed ahead anyway, the story went, and discovered a secret about Shyamalan's past -- a drowning he witnessed as a child -- that provided the impetus for his moody, spooky filmmaking.

A number of media outlets (Zap2it.com included) reported on the story, but Hammer admitted Friday (July 16) that it was false. Hammer says she takes responsibility for the hoax.

A spokeswoman for NBC, which recently took control of the Sci Fi Channel in its merger with Universal, says the "Buried Secret" campaign "is not consistent with our policy. ... We would never intend to offend the public or the press and value our relationship with both."