At least five new books by JD Salinger are set for posthumous release, say biographers for the famously reclusive author.
Authors David Shields and Shane Salerno, cite "two independent and separate sources", who they say have "documented and verified" the information, reports the Associated Press, which obtained a preview copy.
The book - entitled Salinger - is due to be published on 3 September.
Fresh stories about Franny and Zooey's The Glass Family are due, as is a revisit to Holden Caulfield, claims the book. It adds further material will draw on Salinger's World War II years and his interest in eastern religion. The new material will be released starting between 2015 and 2020.
Salinger died aged 92 in 2010, having not published anything since the early 1960s, though he continued to write.
However Salinger's son Matthew said he was sceptical the upcoming book and documentary would deepen understanding of his father.
In an interview with the New York Times, Salinger Jnr said his father had confined his intimate dealings to a circle of seven or eight people.
Salerno responded by gesturing to hundreds of unpublished photographs, letters and diaries belonging to Salinger and his friends, saying: "If that's not the inner circle, I don't know what is the inner circle."
A documentary on the author, also by Salerno, will open on 6 September.
According to The Washington Post, further disclosures include reports Salinger had only one testicle, and that he annulled his marriage to his first wife the half-German, half French Sylvia Welter because he learned she was a Gestapo informant.