INDIANAPOLIS - An Indiana college professor has found rare film footage showing President Franklin Delano Roosevelt being pushed in a wheelchair, depicting a secret not revealed to the public until after his death.

Franklin College professor Ray Begovich said Tuesday he found the eight-second clip while doing research in the National Archives in College Park, Md.

The film clip shows Roosevelt on the U.S.S. Baltimore at Pearl Harbor in July 1944, nine months before his death. The wheelchair is not clearly visible, but its motion is.

The FDR Presidential Museum and Library and the National Archives both say such footage is rare.

Roosevelt contracted polio in 1921 at age 39 and did not publicly appear in a wheelchair throughout his presidency. The FDR museum says news photographers co-operated in concealing his disability.