Harper Lee, author of the classic novel To Kill a Mockingbird, has sued a literary agent who allegedly tricked her into handing him the copyright to the book.
Lee, 87, says Samuel Pinkus took advantage of her poor hearing and sight to transfer the rights and has failed to respond to licence requests.
She says when her long-time agent, Eugene Winick, fell ill in 2002 his son-in-law, Mr Pinkus, switched several of his clients over to his own company.
Mr Pinkus is alleged to have transferred the rights to secure himself "irrevocable" interest in the book's earnings.
It is further alleged that Mr Pinkus failed to respond to offers on e-book rights and questions relating to the book's 50th anniversary.
The suit, filed in a court in Manhattan, New York, aims to re-assign the book's rights to Lee and recover any commission Mr Pinkus has taken since 2007.
To Kill A Mockingbird was published in 1960, winning the Pulitzer Prize for fiction. It has since sold more than 30 million copies.
It tells the story of Atticus Finch, a lawyer who defends a black man wrongly accused of raping a white woman in depression-era community tainted by racism. Finch is often hailed as an American literary hero and was memorably portrayed by Gregory Peck in the Oscar-winning 1962 film adaptation.
The novel is Lee's only published book. She lives in Monroeville, Alabama, is rarely seen in public and declines almost all interview requests.
Mr Pinkus did not immediately respond to an email from Reuters news agency seeking comment.