Director Laura Poitras accepts the award for Best Documentary for her film "Citizenfour" at the 2015 Film Independent Spirit Awards in Santa Monica, California February 21, 2015. [Photo/Agencies]

The Edward Snowden documentary "Citizenfour" has won the Oscar for best documentary.

Laura Poitras' film documents her initial meeting in Hong Kong with Snowden, as well as journalist Glenn Greenwald. It's an uncommonly intimate view of what became a historic and much debated act: Snowden leaking National Security Agency documents that revealed the previously undisclosed collection of Americans' phone and email records.

Snowden was charged under the federal Espionage Act and is currently living in asylum in Russia. Because of the sensitive nature of the footage, Poitras made "Citizenfour" under intense secrecy and edited it in Germany.

The other nominees Sunday were: "Virunga," "Last Days of Vietnam," "The Salt of the Earth" and "Finding Vivian Maier."

The 87th Academy Awards are airing live with Neil Patrick Harris as host.

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