Publishing seductress Judith Regan has gotten away with her vindictive tantrums in the past, but sources say she may have chosen the wrong foe in her former PR director, Paul Crichton. Friends of the well-liked publicist say he hired an attorney to look into a possible libel suit after Regan dispatched a minion to smear him in the New York Post.

“Paul’s lawyer and his friends are all urging him to sue Regan and [Regan Books parent company] HarperCollins for defamation of character, slander, libel, whatever, for what they said about him in the Post,” says a source close to Crichton, referring to last Wednesday’s Page Six item in which Paula Conway—identified as “Regan Media’s interim PR director”—accused the publicist of clearing his desk “at like midnight” and sneaking away after being questioned about “unauthorized spending in his department.”

“It was all a lie—he was never under investigation for anything,” says the source. (HarperCollins reps declined to comment on a departing employee, but a company source confirmed to the New York Daily News’s Lowdown column that there was never an investigation.)

Furthermore, a top-level Regan Books employee said she didn’t know anything about Conway or an “interim PR director.” According to our source, that’s because “Paula is really just a freelance publicist who happens to be a close personal friend of Maureen Regan, Judith’s sister.” The two women are also co-authors of a book called The Beauty Buyble: The Top 100 Beauty Products of 2006, scheduled to be published by Regan’s imprint next year.

The real reason Crichton decided to leave—after shepherding 13 of Regan’s books onto the New York Times best-seller list—was that his boss was working him like a Siberian husky in the Iditarod, says our source. We’re told that the slight, 32-year-old publicist lost 10 pounds after taking on the responsibilities of associate publisher and director of marketing, in addition to his regular duties, when those positions were vacated in July.

“Paul worked his ass off, but Judith was insisting that he sign a three-year contract at the same pay he was receiving before he took on the additional jobs and, on top of that, move to L.A.,” where Regan recently moved her operations, the source says. “When he called her to say he wouldn’t sign and to give notice, she hung up on him. Anyway, you can’t blame him for not looking forward to working with Victoria GottiJanice Dickinson, and Kimora Lee—all of whom have books coming out next year.”

But while rumors have been circulating that Crichton may want to vent some of his frustrations by writing a tell-all detailing his ex-boss’s mean streak and infamous private exploits (like her ill-fated affair with wannabe Homeland Security czar Bernard Kerik; call it, The Devil Wears Nada) the publicist’s pal laughs the notion off, saying, “he’s no Bridie Clark.” Another former Regan Books employee, Clark is already hard at work on a roman à clef about the company—in which staffers are thinly disguised to skirt her confidentiality agreement, entitled Because She Can. Besides, Crichton may not have much time for writing. We’re told he’s starting a new job next Monday.

Crichton himself could not be reached for comment, and calls to a Regan Books publicist were not returned by press time.