Ex-National Security Agency contractor and surveillance whistleblower Edward Snowden's memoir "Permanent Record," due Sept. 17, raises a number of legal issues, one expert says.

Snowden was charged in 2013 with two counts of violating the Espionage Act and one count of theft of government property, and lives in Moscow.

While the story of Snowden’s initial disclosure was captured in both a documentary and a movie, the memoir poses a new set of legal obstacles, national security lawyer Bradley Moss told Law&Crime.

Moss said despite Snowden having already violated his non-disclosure agreement, proceeds from the memoir sales could be seized by the government — unless the book is subjected to a screening process before publication.

"In general, all former U.S. Government security clearance holders are supposed to submit any published works for pre-publication review, no matter how many years ago it was that they held a clearance," he said.

"This process is specifically mandatory for individuals – such as Mr. Snowden – who held access to sensitive compartmented information. Each agency has its own pre-publication review process, but the general concept is that the individual submits the draft manuscript to the agency for review."

"Once the agency completes the review process, they'll send the manuscript back with any redactions that are required as implicating currently classified information," he added.

According to Moss, courts have consistently frowned upon any attempts to publish content that might be subject to NDA mandates without giving the government the opportunity to screen the content.

"The courts have repeatedly concluded that if the individual does not go through this specific process where mandated, and the government chooses to pursue either civil litigation or criminal charges, the individual will be found to be in breach of their contractual obligations as a clearance holder," Moss told Law&Crime.

The Associated Press reported the book was considered a "covert project" by Macmillan and only identified under code names in internal documents. Financial details for the book have not been released.

"If a civil lawsuit is filed, the government typically seeks to seize all monetary proceeds from sales of the book, no matter whether the individual was going to personally take the proceeds as income or donate them to charity," Moss said.

"If criminal charges are filed, it is for the knowing and deliberate disclosure of classified information without authorization, and is a felony with possible jail time in play."