The review was ordered after a pair of historians put forth evidence suggesting that the Marines misidentified one of the men immortalized in the photograph by Associated Press photographer Joe Rosenthal.
"Rosenthal's photo captured a single moment in the 36-day battle during which more than 6,500 U.S. servicemen made the ultimate sacrifice for our nation and it is representative of the more than 70,000 U.S. Marines, Sailors, Soldiers and Coast Guardsmen that took part in the battle" the Marines said in a statement. "We are humbled by the service and sacrifice of all who fought on Iwo Jima."
President Franklin D. Roosevelt himself had ordered the Marines to track down the names of the six men depicted in the picture.
They were identified as John Bradley, Harlon Block, Rene Gagnon, Ira Hayes, Franklin Sousley and Michael Strank.
All were Marines except Bradley, who was a Navy corpsman — and whose son, James, wrote the best-seling "Flags of Our Fathers" book that Clint Eastwood turned into a movie.
Block, Strank and Sousley died fighting on Iwo Jima. The surviving trio became national heroes.
But historians Eric Krelle, of Omaha, Nebraska, and Stephen Foley, who lives in Ireland, contend the Marine identified as Sousley was actually a private named Harold Henry Schultz, who died in 1995. They also maintain the man identified as Bradley was Sousley.
If true, that means Bradley wasn't in the photo. He died in 1994.
"This is unbelievable," Bradley's son told the Associated Press. "I'm interested in facts and truths, so that's fine, but I don't know what's happening."
This story originally appeared on NBCNews.com.