The Twisted Tongues — John Burke

A wartime traitor who broadcast from Germany is finally released from prison. Nobody wanted to listen to him during the war and nobody wants to listen to him now. But he intends to be heard, and when he begins to write his memoirs for a newspaper, old ghosts stir uneasily and it becomes a race against time: will he reveal the truth behind the smug respectability of men in high places before they find a means of silencing him forever?