In the 1970’s a set of 34 photographs known as The Cockburn-Lange Collection and claimed to have been taken by a British pilot in actual WW1 combat were donated to the Smithsonian’s National Air and Space Museum.
In 1985, in an article in the enthusiast magazine Cross and Cockade, the British Society of WW1 Aero Historians revealed that these photographs were faked by an American named Wesley D. Archer, who had served briefly in the Royal Air Force in 1918 and later embarked on a career in model-making. They even uncovered a photograph of Archer actually staging one of his fakes.
You can read the whole story here. The Smithsonian now informs anyone who requests permission to use any of these photographs that they aren’t real.