After reviewing an Ex-Navy SEAL's book that tells "the real story" behind the killing of Osama Bin Laden, the Pentagon has announced that the author is in "material breach" of non-disclosure agreements and warned him it is considering legal action against him as a result. It added that it is considering legal action against all those "acting in concert" with the SEAL on his book, "No Easy Day," which is scheduled to be released Tuesday.

A letter by Pentagon general counsel Jeh Johnson informed the former SEAL that he had violated non-disclosure agreements against releasing classified information.

"In the judgment of the Department of Defense, you are in material breach and violation of the non-disclosure agreements you signed," wrote Johnson. "Further public dissemination of your book will aggravate your breach and violation of your agreements."

Johnson said the department is considering pursuing "all remedies legally available to us."

The letter was addressed to the author's pseudonym, "Mark Owen," because the Pentagon will not publicly reveal the SEAL's real name.

The letter noted that, in January 2007, "Owen" signed two non-disclosure agreements with the Navy, and though he is no longer in the military, "you have a continuing obligation to 'never divulge' classified information."

Furthermore, the letter added, "this commitment remains in force even after you left the active duty Navy."

Johnson noted that in signing the agreements the SEAL, "acknowledged your awareness that disclosure of classified information constitutes a violation of federal criminal law. It also meant he would submit any manuscript to the Pentagon for a security review, as well as obtain permission."

Dutton announced the book's pending release last week, saying that "No Easy Day" will "set the record straight" on the bin Laden operation. While the author is listed under the pseudonym of Mark Owen, and the publisher had asked news organizations to withhold his identity, Fox News first reported the author was former Navy SEAL chief Matt Bissonnette of Alaska who retired last summer.

After the initial burst of publicity, the book shot up to the top of the Amazon.com chart, reaching No. 1 as of late Friday morning and remaining there Monday, displacing the hugely popular erotic trilogy "Fifty Shades of Gray."

Bissonnette did not submit the book for pre-publication review that is required by the military secrecy agreements officials say he signed.

Pentagon regulations stipulate that retired personnel, former employees and non-active duty members of the Reserves "shall use the DoD security review process to ensure that information they submit for public release does not compromise national security."

"Owen" has almost exclusively spoken through his publisher and has previously said the book was written so that it did not betray any sensitive information. The publisher added that the book was vetted by a "former special operations attorney."

Though the former SEAL said he will donate a majority of the book's profits to charities that help the families of fallen SEALs, the letter suggested that all of the book's royalties belong to the U.S. government.

In signing his non-disclosure agreements, the former SEAL acknowledged he "assigned to the U.S. government ... 'all royalties, remunerations, and emoluments that have resulted, will result or may result from a disclosure, publication or revelation of classified information not consistent with the terms of this agreement,'" the letter added.

After the initial burst of publicity, the book shot up to the top of the Amazon.com chart, reaching No. 1 as of late Friday morning and remaining there Monday, displacing the hugely popular erotic trilogy "Fifty Shades of Grey."

One Navy SEAL told Fox News, "How do we tell our guys to stay quiet when this guy won't?" Other SEALs are expressing anger, with some going so far as to call him a "traitor."

And Col. Tim Nye, a Special Operations Command spokesman, said the author "put himself in danger" by writing the book.

"This individual came forward. He started the process. He had to have known where this would lead," Nye said. "He's the one who started this so he bears the ultimate responsibility for this."

"No Easy Day," is scheduled for publication on Sept. 11.