John Le Carre: I think my father conned the Stasi

John le Carre's latest novel A Legacy of Spies is published on Thursday - always an anticipated event for his legions of readers. But this time it involves the return of his master spy, George Smiley.

The Today programme's Jim Naughtie has been speaking to the author and former spy about his writing, his own life and discovering the Stasi file kept on his father.