Harper Lee: Article on In Cold Blood murders allegedly by To Kill A Mockingbird author surfaces online

Lee's biographer links author to an article in The Grapevine

Harper Lee’s ‘To Kill a Mockingbird’ has sold in excess of 30 million copies (Getty)

The biographer of Harper Lee has allegedly discovered an article the novelist wrote about the real-life quadruple murders at the centre of Truman Capote novel In Cold Blood.

According to The Guardian, Charles J Shields found the piece which Lee, who passed away earlier this year, wrote for a March 1960 edition of FBI Magazine Grapevine.

The article - written without Lee's byline - is a reportage on the notorious Clutter family murders which were the source of Capote's 1966 non-fiction novel; a longtime friend of the writer, she assisted him on his famous New Yorker assignment and reported on the community's reaction to the brutal killings.

Clipping from The Garden City Telegram, saying how Lee was to write an article on the Clutter Murders for The Grapevine (The Garden City Telegram)

Part of an alleged article by Harper Lee, published in The Grapevine (The Grapevine)

Herb and Bonnie Clutter and their teenage children Nancy and Kenyon were slaughtered by Dick Hickock and Perry Edward Smith in their own Kansas home in 1959.

Describing the events as "the most extraordinary murder case in the history of the state," Lee's article included interviews with Alvin Dewey, the detective leading the FBI investigation, which Capote used as research for In Cold Blood.

Shields is said to have unearthed the piece while in the process of revising his 2006 bestselling biography Mockingbird: a Portrait of Harper Lee.

Garden City Telegram writer Dolores Hope introduced the article by saying: “Nelle Harper Lee, young writer who came to Garden City with Truman Capote to gather material for a New Yorker magazine article on the Clutter case, wrote the piece. Miss Harper’s first novel is due for publication … this spring and advance reports say it is bound to be a success.”

The novel Hope referred to was To Kill a Mockingbird which is considered one of the greatest literary successes of the 20th century.

Grapevine is set to reprint Lee's article next month, with Shield including his findings in Mockingbird: a Portrait of Harper Lee: From Scout to Go Set a Watchman which will be published by Henry Holt on Tuesday.