After nearly three-quarters of a century Robert Capa’s “Falling Soldier” picture from the Spanish Civil War remains one of the most famous images of combat ever. It is also one of the most debated, with a long string of critics claiming that the photo, of a soldier seemingly at the moment of death, was faked. Now, a new book by a Spanish researcher asserts that the picture could not have been made where, when or how Capa’s admirers and heirs have claimed.

In “Shadows of Photography,” José Manuel Susperregui, a communications professor at the Universidad del País Vasco, concludes that Capa’s picture was taken not at Cerro Muriano, just north of Córdoba, but near another town, about 35 miles away. Since that location was far from the battle lines when Capa was there, Mr. Susperregui said, it means that “the ‘Falling Soldier’ photo is staged, as are all the others in the series taken on that front.”

Experts at the International Center of Photography in Manhattan, where Capa’s archive is stored, said they found some aspects of Mr. Susperregui’s investigation intriguing or even convincing. But they continue to believe that the image seen in “Falling Soldier” is genuine, and caution against jumping to conclusions. “Part of what is difficult about this is that people are saying, ‘Well if it’s not here, but there, then, good God, it’s fabricated,’ ” Willis E. Hartshorn, the center’s director, said in an interview. “That’s a leap that I think needs a lot more research and a lot more study.”

Image Robert Capas "Falling Soldier," from the Spanish Civil War has drawn both acclaim and questions over its veracity. Credit... Robert Capa/Magnum Photos

Mr. Susperregui said he began his inquiry by examining the background of other photographs from the same sequence as that of the “Falling Soldier,” pictures in which a mountain range can be seen in the distance. He then e-mailed the clearest of those images to librarians and historians in towns around Córdoba, asking if they recognized the landscape, and eventually got a positive response from a community called Espejo.