The photo was taken in September 2010 in Sangin Province, Afghanistan. It depicts Marines posing in front of a flag bearing the letters "SS."
A Marine sniper who wished to remain anonymous said the argument that the flag was meant to represent Nazi ideals was "absurd," and the flag holds meaning to the sniper community.
The Marine confirmed that the initials represent "Scout Sniper" and "Sharp Shooter." The initials are also used on military maps to indicate locations of sniper teams.
The Marines in the photograph are no longer with the unit they were assigned to at the time.
The Marine Corps is currently investigating a group of Marines recorded on video urinating on the dead bodies of Taliban fighters.
Those Marines were based at Camp Lejune, N.C.