Alan Arkin may join Ben Affleck's 'Argo'

Alan Arkin is reportedly close to joining the cast of Ben Affleck's CIA drama Argo.

According to Variety, Arkin is in negotiations to join Affleck's next directorial project as an ex-CIA agent called Lester Seigel.

The film follows a secret CIA mission to rescue six diplomats being held hostage in Iran in 1979, by convincing the authorities that they were there filming a science fiction film.

If cast, Arkin will play a Hollywood producer who used to be an agent himself, who is drafted in to assist on the mission.

Arkin is best known for his Academy Award-winning role in Little Miss Sunshine and will next be seen opposite Ryan Reynolds in The Change-Up.

Affleck had been linked to a role in Baz Luhrmann's upcoming adaptation of The Great Gatsby, but is said to have dropped out in order to focus fully on Argo.