The Pentagon has threatened legal action against the former Navy SEAL who has authored a forthcoming book describing details of the raid that killed Osama bin Laden.

The Pentagon’s top lawyer has informed the former SEAL he has violated agreements to not divulge military secrets.

General counsel of the US Defence Department, Jeh Johnson, wrote in a letter transmitted to the author on Thursday that he had signed two nondisclosure agreements with the Navy in 2007 that obliged him to “never divulge” classified information.

Johnson said after reviewing a copy of the book, No Easy Day, the Pentagon concluded the author is in “material breach and violation” of the agreements.

He said the department was considering pursuing against him “all remedies legally available to us”.

Johnson addressed the letter to Mr “Mark Owen”, using quotation marks to signify the author’s pseudonym. His real name is Matt Bissonnette.

Bissonnette referred requests for comment about the letter on Friday to his publisher, who was not immediately available.

Bin Laden apparently was shot in the head when he looked out of his bedroom door into the top-floor hallway of his compound as SEALs rushed up a narrow stairwell in his direction, according to Bissonnette.

This contradicts previous accounts by administration officials, raising questions as to whether the terror mastermind presented a clear threat when SEALs first fired upon him.

No Easy Day is scheduled to be published next week by Penguin Group (USA)’s Dutton imprint.