The Illinois senator had said during a Memorial Day appearance in New Mexico Monday that an uncle had helped liberate the Nazi death camp at Auschwitz, The New York Times reported. Actually, it was his maternal great uncle, Charlie Payne, and it was a sub-camp of a different Nazi concentration camp, Buchenwald, an Obama spokesman said. The prisoners at Auschwitz were freed by Soviet troops.

"Senator Obama's family is proud of the service of his grandfather and uncles in World War II -- especially the fact that his great uncle was a part of liberating one of the concentration camps at Buchenwald," Bill Burton said in a statement. "Yesterday he mistakenly referred to Auschwitz instead of Buchenwald in telling of his personal experience of a soldier in his family who served heroically."

Payne, a member of the 89th Infantry Division, was among the U.S. forces that liberated Ohrdruf.

The Republican National Committee had distributed a copy of a story that questioned the Memorial Day claim, the Times reported.