Watergate figure John Dean, who once spent eight years embroiled in a libel suit against a publishing house, is now threatening to sue a college history professor for posting audio tapes online that suggest the Nixon confidant-turned-government witness is covering up the details of his role in the most infamous political scandal in American history.

Dean, the former White House counsel whose damning testimony led to President Richard Nixon's resignation in 1974, is continuing what critics call a pattern of frivolous lawsuits meant to stifle questions about his role in Watergate. Now, a historian who runs a Web site dedicated to the Nixon tapes is feeling that pressure.

"I want to minimize my legal exposure," said Luke Nichter, the Texas A&M professor who runs Nixontapes.org, and who dropped two audio files from his Web site after receiving threats from Dean demanding that they be removed.

"It's an incident of a much broader pattern that this is how Dean treats people who present information contrary to his views."

Nichter had posted a 1989 phone call in which Dean disavowed the accuracy of his memoir, "Blind Ambition," the national bestseller that helped establish the public's view of the conspiracy to break into the Democratic National Committee headquarters in 1972.

"What happened is, the editors got real excited, interesting, wanted to make it more intriguing. That's why all that shit got in there," Dean said in the phone call, referring to material in his book he said was inaccurate. "I never actually went back and re-read my testimony when I was writing my book." The recording is still available at Watergate.com.

Nichter set those admissions against a 4-minute tape from a June 2009 speech Dean gave at the Nixon Library promoting the re-release of his memoir. Dean's new edition did not change the content he has disavowed as the creation of zealous editors, though he added a 95-page afterword.

"I merely wanted to bring these contradictions to light and thought I was doing a service, but Dean was absolutely mortified when he found out that I had these materials," Nichter told FOXNews.com.

Nichter says he is interested in full disclosure of Watergate documents and doesn't "take a side" in the decades-old clashes.

"It seems to be an issue of free speech and academic freedom and I'm sort of caught in the middle," Nichter said.

Dean, who pleaded guilty to obstruction of justice for his role in covering up the Watergate burglaries, disagreed. In e-mails obtained by FOXNews.com he threatened to sue because Nichter posted recordings he did not make himself. (The phone call was provided to Nichter by a Florida State Attorney's Office; the speech came from an anonymous source.)

"Lawsuits are legalized brawls and costly to both sides. But if you believe you can roll over me so easily, you are mistaken," the 70-year-old Dean wrote.

Dean argued that the recordings were made without his consent and violated his common law copyright, meaning that no one had the right to publish his speech and conversation in their entirety without his consent.

Legal experts contacted by FOXNews.com said that Nixontapes.org could not publish Dean's entire speech, but could run segments without Dean's approval, which is what Nichter was doing before he received the warning from Dean.

"To the extent that the Web site used the speech to comment on or criticize Dean, it may well have a strong fair-use argument," said Kurt Opsahl, a senior staff attorney with the Electric Frontier Foundation. That would allow Nixontapes.org to provide a portion of the audio without Dean's authorization.

And common law copyright wouldn't cover the informal conversation in the 1989 phone call, said Professor Tyler S. Ochoa of the High Tech Law Institute at Santa Clara University School of Law. Even if it were applied in court, "it is outweighed by the interest in free speech," he said.

Several authors and journalists who spoke to FOXNews.com said Dean uses the threat of litigation as a bullying tactic to silence his critics. Some would not speak for fear of being sued by Dean, including Jim Hougan, who wrote the first revisionist history of Watergate, 1984's "Secret Agenda."

"I can't talk about this because I am afraid John Dean will sue me," Hougan wrote in an e-mail to FOXNews.com. Hougan was one of many targets in a lawsuit instigated by Dean in 1992.

"He's very quick to react and threaten legal action and most of the time people back down," Nichter said.

Dean has also threatened FOX News correspondent James Rosen with a lawsuit over his 2008 biography of former Attorney General John Mitchell, "The Strong Man," which pointed to Dean as the leading figure in the planning of Watergate.

"I will probably deal with [Rosen] in court," Dean told a writer for the left-wing Web site Counterpunch. "His material, to put it mildly, is bullshit."

Contacted for this article, Rosen replied: "My book speaks for itself, and I think it's noteworthy that Dean has entirely avoided engaging its substance. Dean himself is well aware that his historical reputation has suffered enormously in the last two decades, and so he resorts to frivolous litigation and bullying tactics to rehabilitate himself. Not since Albert Speer [a Nazi minister convicted at the Nuremberg Trials] has a historical figure so assiduously used his post-prison writings to muddy and distort the historical record of the events in which he was culpable."
Dean refused repeated requests from FOXNews.com for comment.

Nichter said he cannot afford a costly legal battle and is abiding Dean's wishes for now, leaving the audio files noticeably absent from his Web site.

"He took off work for eight or nine years to devote himself and his full resources" to his lawsuit against St. Martin's Press, Nichter said. "That's certainly not a financial position that I'm in or most people [are in]. That's why most people back down."

But for Nichter, Dean and many others, the unanswered questions surrounding Watergate are not simply a historical controversy — they remain deadly serious more than 35 years later.
"This was not some inconsequential testimony" that Dean provided on Watergate, Nichter said. "People did time for what John Dean said. A president came down."