Argo, Zero Dark Thirty and Searching for Sugar Man have scooped the top screenplay honours from the Writers Guild of America.

The adapted screenplay award went to Argo writer Chris Terrio. The film, directed by Ben Affleck, is based on the 1980 CIA operation to extract six US personnel out of revolutionary Iran.

Terrio based his screenplay on The Master of Disguise, a book written by Antonio J Mendez on whom Affleck’s lead character is based, and Wired magazine article The Great Escape by Joshuah Bearman.

It beat competition from the writers of Life of Pi, Lincoln, The Perks of Being a Wallflower and Silver Linings Playbook.

It adds to Argo’s awards haul, which includes trophies for best film and director at both the BAFTAs and Golden Globes, and builds momentum for the Academy Awards, where the film has garnered seven nominations.

Zero Dark Thirty writer, Mark Boal, picked up the original screenplay prize at the awards, which were unveiled simultaneously at ceremonies on Sunday night (Feb 17) held by the WGA West in Los Angeles and WGA East in New York City.

The film, about the hunt for Osama bin Laden, beat nominees for Flight, Looper, The Master and Moonrise Kingdom.

In addition, Searching for Sugar Man saw Malik Bendjelloul win for best documentary screenplay.

The story about the hunt for enigmatic US musician Rodriguez beat competition from The Central Park Five, The Invisible War, Mea Maxima Culpa: Silence in the House of God, We Are Legion: the Story of the Hacktivists andWest of Memphis.