WASHINGTON — It is an iconic photograph of American patriotism, depicting the heroism of service members raising the flag over Iwo Jima during World War II, which inspired the book and movie “Flags of Our Fathers.”

But while the image has become a symbol of the sacrifices of American troops, the Marine Corps has also had to defend it for 70 years against accusations that it was staged and that some of the men were misidentified.

Now, the man who wrote the best-selling book, which chronicled how his father and five Marines came together to lift the flag in the famous photograph, has raised new doubts about the image, saying that he now believes his father is not actually in it.

The author, James Bradley, revealed his conclusion in an interview on Tuesday, just days after the Marine Corps said that it had opened an inquiry into whether the identifications in the photograph were correct.