Maciej Kowalczyk said Monday he found the file on Baron Manfred Albrecht von Richthofen while going through old German archives in Ostrow Wielkopolski, in western Poland. The area was formerly German, and Richthofen was briefly stationed there.
The certificate does not cast any light on who shot the famous WWI pilot down - Australian ground forces or Canadian pilot Roy Brown.
But Kowalczyk says it is notable how Germany's top fighter ace, with 80 kills, was treated like any other casualty in death.
The one-page report misspells Richthofen's name and says simply he "died from wound sustained in combat."