Los Angeles - An eagerly awaited Hollywood film about the hunt for Osama bin Laden is being tipped as a likely Oscar favourite in early reviews released on Monday.

Zero Dark Thirty is directed by Kathryn Bigelow, the first female director to win an Oscar for her 2008 Iraq war movie The Hurt Locker.

Her latest film has been courting controversy since it was first announced, as opposition Republicans accused the White House of giving her team special access to classified material in the hope that the film would persuade voters to re-elect President Barack Obama in the November election.

A delay in the release pushed the film past the November 6 elections. The film will now go into general release on January 11, but will qualify for the Oscars with a limited opening at the end of December.

According to trade publication The Hollywood Reporter, the two-and-a-half hour film steers clear of the political backstory in favour of focusing on a female CIA agent played by Jessica Chastain, whose perseverance enabled her to track down the al-Qaeda leader, leading to a commando raid to capture or kill him.

“There's essentially no Bush or Cheney, no Iraq War, no Obama announcing the success of the May 2, 2011, raid on Bin Laden's in-plain-sight Pakistani compound,” The Hollywood Reporter said.

Time magazine reviewer Richard Corliss praised the film's verisimilitude and its success in avoiding the usual Hollywood cliches.

“This is movie journalism that snaps and sings, that purifies a decade's clamour and clutter into narrative clarity, with a salutary kick,” he said.

“Bin Laden film's focus is facts, not flash,” was the headline in The New York Times, which drew attention to the bleak opening of the film, which focuses on gruesome torture scenes as the CIA tries to pry information from captives.

“The new movie is not for the faint of heart or for those expecting typical Hollywood fare,” the paper wrote.

“There's not an extra beat in the film, not a wasted scene,” added the reviewer for the website HitFix. “This may not be like any other thriller I can name, but that's one way you can tell that Bigelow has done something special here.” - Sapa-dpa