US director Kathryn Bigelow defended her controversial Oscar-tipped movie \"Zero Dark Thirty\" against criticism of its depiction of torture in the hunt for Osama bin Laden. Writing in the Los Angeles Times, she said critics should focus on those responsible for torture and harsh interrogation techniques in the years after 9/11, rather than at artists portraying them. \"Experts disagree sharply on the facts and particulars of the intelligence hunt, and doubtlessly that debate will continue,\" wrote Bigelow, whose 2008 film \"The Hurt Locker\" won six Oscars including best picture and best director. \"As for what I personally believe, which has been the subject of inquiries, accusations and speculation, I think Osama bin Laden was found due to ingenious detective work. \"Torture was, however, as we all know, employed in the early years of the hunt. That doesn\'t mean it was the key to finding Bin Laden. It means it is a part of the story we couldn\'t ignore.\" The movie, which went on national US release at the weekend after a limited release in December to qualify for Hollywood\'s awards season, tells the story of the decade-long manhunt for the al-Qaeda chief after 9/11. It includes graphic depiction of water-boarding and other harsh techniques, and alludes to the changing CIA culture that came about after President Barack Obama came to office in 2009. It has drawn criticism notably from acting CIA director Michael Morell, who issued a statement about it last month. \"The film creates the strong impression that the enhanced interrogation techniques that were part of our former detention and interrogation program were the key to finding Bin Laden. That impression is false,\" he said. Bigelow wrote Wednesday that \"depiction is not endorsement,\" adding: \"I do wonder if some of the sentiments expressed about the film might be more appropriately directed at those who instituted and ordered these US policies, as opposed to a motion picture that brings the story to the screen.\" Actress Jessica Chastain, who plays the relentless CIA agent credited with driving the Bin Laden manhunt, won the best drama actress award at the Golden Globes on Sunday. \"Zero Dark Thirty\" is nominated in five categories for this year\'s Academy Awards, including best film - although not for best director, in what some see as a snub following the controversy the movie has generated. The Oscars, the climax to Hollywood\'s annual awards season, are to be announced on February 24.