Washington (CNN) -- The Pentagon general counsel threatened legal action Thursday against a former Navy SEAL who wrote a revealing book about last year's Osama bin Laden raid, warning him he has violated secrecy agreements and broken federal law. 

In a letter addressed to "Mark Owen," the pen name of book author Matt Bissonnette, General Counsel Jeh Charles Johnson wrote the Pentagon is considering pursuing "all remedies legally available" against the former SEAL and his publisher, Penguin Putnam. 

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

The book is called "No Easy Day" and is a gripping account of the Navy SEAL raid on bin Laden's compound in Pakistan last year that ended in the death of the world's most notorious terrorist leader. 

The story sheds more light on the now famous skill and daring of the SEALs. But the book's very existence stoked controversy because members of the elite unit don't usually divulge details of their operations. 

The book is one of several accounts about the operation to have surfaced after last year's raid. 

Buzz ramps up over SEAL's bin Laden book 

Government officials only recently became aware the former SEAL was writing a book, but they were told it encompassed more than just the raid and included vignettes from training and other missions. 

They wanted to see a copy, a Defense Department official said, to make sure no classified information would be released and to see if the book contained any information that might identify other team members. 
What is the pen name on the book?
Mark Owen