The American novelist, best known for writing To Kill a Mockingbird, has passed away aged 89.

The American author Harper Lee, best known for writing the novel To Kill a Mockingbird, has died aged 89. A statement released by Lee’s attorney, Tonja Carter, said: “Lee has passed away early this morning in her sleep,” adding that her death was unexpected.

Lee’s seminal novel, about Atticus Finch, a respectable lawyer who confronts the ingrained racial prejudices in the Southern United States when he defends a black man accused of raping a white woman, is considered to be one of the most significant contributions to American literature of the past century. The author received one of America’s highest honours, the Pulitzer Prize, for To Kill a Mockingbird, in recognition of her valuable study of race in American society.

For decades it seemed that this extraordinary book would be her sole literary accomplishment until Lee shocked the world by releasing a sequel, Go Set a Watchman, in 2015. The surprising appearance of Lee’s second novel became the literary sensation of the year, and smashed sales records in the U.S., with over 1.1 million copies of the book selling...