The author of To Kill A Mockingbird has sued a literary agent she says tricked her into assigning him the copyright on the Pulitzer Prize-winning book. Harper Lee, 87, says Samuel Pinkus took advantage of her failing hearing and eyesight to transfer the rights and has failed to respond to licence requests. To Kill A Mockingbird was published in 1960 and is considered a classic. It has sold more than 30 million copies. Lee is rarely seen in public and declines almost all interview requests. The novel is the only published book by the author, who lives in Monroeville, Alabama.