Imposter (2002)

The year is 2079. The earth has been at war with an alien force for over a decade. Spencer Olham is a lauded government scientist whose latest work promises to save the planet. But suddenly he is accused of being an alien spy, and becomes the subject of a nationwide manhunt. Olham is faced with a two-tiered dilemma--can he prove his identity to the secret police in time to help mankind? Can he ultimately prove his identity to himself?