The director and screenwriter of Oscar nominated Best Picture Zero Dark Thirty have dodged a U.S. Senate Intelligence Committee investigation into where they obtained information for the gripping movie.

Kathryn Bigelow and Mark Boal have been dogged by reports suggesting they were given access to classified files as they researched the film, which stars Jessica Chastain as a Cia agent leading America's hunt for terrorist mastermind Osama bin Laden, ever since the hard-hitting project hit cinemas last year (Dec12).

The rumours sparked a high-level investigation led by former U.S. presidential candidate Senator John MCCain, which has now been closed down, according to Reuters.

The good news comes a day after Boal, Bigelow and Chastain missed out on director, screenplay and leading actress awards at the Oscars on Sunday night (24Feb13).

Zero Dark Thirty would have been shut out had it not been for a Sound Editing trophy tie with Skyfall.