The footage comes from a copy made before distributors cut
Lost scenes from the classic sci-fi film Metropolis have been shown for the first time in decades.
The long-lost original cut of Fritz Lang's 1927 silent film was discovered in the archives of the Museum of Cinema in Buenos Aires earlier this year.
The museum's Paula Felix-Didier said it was the only copy of the complete film.
Metropolis depicts a 21st Century society divided between a class of underworld workers and the "thinkers" above who control them.
Soon after its initial release at the height of Germany's Weimar Republic, distributors cut Lang's three-and-a-half-hour masterpiece into the shorter version since viewed by millions worldwide.
But a private collector carried an original print to Argentina in 1928, where it has stayed, Felix-Didier said.
In the 1980s, Argentine film fanatic Fernando Pena heard about a man who had propped up a broken projector for "hours" to screen Metropolis in the 1960s - but the version of the film he knew was only one-and-a-half hours long.
For years, he begged the Buenos Aires' museum to check their archives for the man's longer version.
This year, museum researchers finally agreed and in April uncovered the reels in the museum's archive.
The scenes were shown for the first time to a group of journalists
In June, Felix-Didier flew with a DVD to the Friedrich Wilhelm Murnau Foundation in Wiesbaden, Germany, which owns the rights to Metropolis. They confirmed that the extra scenes were from the original.
"We were overjoyed when we heard about the find," Helmut Possmann, head of the foundation, told Reuters.
"We no longer believed we'd see this. Time and again we had had calls about supposed footage but were disappointed."
Around 20 to 25 minutes of footage that fleshes out secondary characters and sheds light on the plot would be added to the film pending restoration, Possmann said, but around 5 minutes of the original was probably still missing.
Released in 1927, the silent film was not a commercial success and nearly ruined the studio behind it.
Soon after its premiere, the movie was heavily cut to make it more accessible, and several new versions of varying lengths emerged.
"The film hasn't left the museum and it won't leave until the city government and the Murnau Foundation decide what to do," Felix-Didier said.