Anti-torture campaigners wearing orange jumpsuits and black hoods staged a high-profile protest outside the Washington DC premiere of controversial Oscar-tipped film Zero Dark Thirty last night.

Holding placards stating "torture is wrong" and branding Kathryn Bigelow and Mark Boal's film about the hunt for Osama bin Laden a "Pentagon-sanctioned movie" the protestors made a cacophony of noise outside the Newseum centre in central Washington as journalists, politicians and members of US president Barack Obama's administration filed into the auditorium. There was also a separate protest organised by so-called "Truthers," who believe the 9/11 attacks were orchestrated by the US government.

Zero Dark Thirty's status as one of the frontrunners for next month's Oscars has been overshadowed by criticism from commentators and politicians over its depiction of the use of torture in the hunt for Bin Laden. Guardian writer Naomi Wolf last week compared Bigelow with the infamous Nazi propagandist Leni Riefenstahl, while both the former Republican US presidential candidate John McCain and the Democratic chair of the Senate intelligence committee, Dianne Feinstein, have suggested Bigelow and Boal endorsed the use of torture by their depiction of its use. The committee is currently probing whether the pair were granted "inappropriate access" to classified CIA material. The politicians have argued that torture was not used in the hunt for Bin Laden and have written to studio Sony to express their "disappointment" that Zero Dark Thirty suggests otherwise.

Speaking inside the Newseum ahead of the film's screening, Bigelow said she and Boal had been "truly awed by the remarkable national conversation that this movie has spurred". She said: "As film-makers, nothing is more flattering, humbling (and intimidating) than creating a film that inspires thoughtful dialogue and debate on topics that are relevant and important. To be clear, we had no agenda in making this film and were not trying to generate controversy. Quite the contrary. Mark and I wanted to present the story as we understood it, based on the extraordinary research that Mark did."

Zero Dark Thirty, which stars Jessica Chastain, Joel Edgerton and Jason Clarke, has received considerable praise from critics and has already been honoured by bodies such as the Alliance of Women Film Journalists and critics groups in Vancouver, New York, LA and Boston. It is up for four Golden Globe prizes and is expected to be among the contenders when the nominees for the 85th Academy Awards are named tomorrow.

Text of Bigelow's premiere speech

Mark and I are truly awed by the remarkable national conversation that this movie has spurred.

As film-makers, nothing is more flattering, humbling (and intimidating) than creating a film that inspires thoughtful dialogue and debate on topics that are relevant and important.

To be clear, we had no agenda in making this film and were not trying to generate controversy. Quite the contrary. Mark and I wanted to present the story as we understood it, based on the extraordinary research that Mark did.

All of us were affected by September 11th, 2001 and the events that followed. Among other things, it catalyzed the greatest manhunt in history. Many of us know how it ended. Perhaps nobody knows every detail of how it happened. We tried to bring this story to the screen in a faithful way.

As a director, I make a film, and then it is up to the audience to interpret. Each person will have their own experience with the film.

This was a momentous part of our nation's history and we wanted to illustrate the ambiguities, the contradictions, and complexities of this 10-year search.

There is a tremendous debate going on about various aspects of the hunt, some of which are depicted in this film. One thing is clear, at the end of the day it took a selfless team of individuals, many of whom we will never know or meet, to carry out this mission. As film-makers, we hope that this film honours their work and sacrifice.