What was the first found footage movie?

The first found footage movie is often considered to be "Cannibal Holocaust," released in 1980 by director Ruggero Deodato. The film presents itself as a documentary, claiming to be a recovered film made by a documentary crew that disappeared in the Amazon rainforest. Its controversial content and realistic presentation sparked significant debate about the ethics of filmmaking and the portrayal of violence. While earlier films had elements of found footage, "Cannibal Holocaust" is the most influential in establishing the genre.