I am an IMDB credited actor in an Oscar winning film. I had a high school friend whose mom was a history professor at the University of Pittsburgh. She served on the board of the Johnstown Flood Museum and in observation of the 100th anniversary of the 1889 flood the museum went through some major upgrades including doing a film to be shown to museum visitors. Charles Guggenheim was engaged to write and direct the film and my friend's mom asked us to be in it. It ended up winning an Oscar for best shot documentary that year.
I played the role of an Italian roadworker who was part of a crew called to reinforce the dam before it burst, flooding the city. I was swept away and drowned. To this day, I'm certain Dicaprio mimicked my performance for this role in Titanic :)