Harper Lee, the author of To Kill A Mockingbird, has sued her literary agent for allegedly duping her into assigning him the copyright on the Pulitzer Prize-winning novel.

In the lawsuit filed in federal court in Manhattan, Lee says Samuel Pinkus, the son-in-law of Lee's long-time agent, Eugene Winick, took advantage of her failing hearing and eyesight to transfer the rights on the book, which has sold more than 30 million copies worldwide and became an Oscar-winning film.

The 87-year-old says she has no memory of agreeing to relinquish her rights or signing the agreement that cements the purported transfer.

Winick had represented Lee for more than 40 years. When he became ill in 2002, Pinkus diverted several of his father-in-law's clients to his own company, the lawsuit said.

According to the lawsuit, in 2007 Pinkus "engaged in a scheme to dupe" Lee into assigning the novel's copyright without any payment and had since failed to respond to licence requests.

To Kill a Mockingbird is the only published book by the author, who lives in Monroeville, Alabama, and is rarely seen in public.

It is also alleged that Pinkus failed to respond to offers on e-book rights and a request for assistance related to the book's 50th anniversary.

The lawsuit asks the court to assign any rights in the book owned by Pinkus to Lee and requests that he hand over any commission he took from 2007 onwards.

The novel tells the story of lawyer Atticus Finch's defence of a black man charged with the rape of a white girl through the eyes of his children Scout and Jem Finch. It takes its title from Finch's advice to his children: "Shoot all the Bluejays you want, if you can hit 'em, but remember it's a sin to kill a Mockingbird."

Among the book's many fans are Oprah Winfrey, Truman Capote and George W Bush – who awarded Lee the Presidential Medal of Freedom for her "outstanding contribution to America's literary tradition".