Truman Capote spent much of his childhood in Monroeville

The collection, assembled by his cousin Jennings Faulk Carter, goes on show in Monroeville, Alabama, later this month.

It includes letters written to his aunt about his childhood friend, Harper Lee, author of To Kill A Mockingbird.

His life story was dramatised in the film Capote, which saw Philip Seymour Hoffman named best actor.

Capote was born in New Orleans in 1924, but was often left with distant cousins in Monroeville, including spending two years there before his mother moved to New York in 1932. He died in Los Angeles in 1984, aged 59.

In one letter, dated 9 July 1959, Capote tells his aunt that Lee, known to her family by her first name of Nelle, was working on a novel.

"Yes, it is true that Nelle Lee is publishing a book... I liked it very much, she has real talent," he wrote.

'Oh so exhausting'

Philip Seymour Hoffman played Capote in the recent film

He also wrote about his friendship with hard-living actress Tallulah Bankhead, commenting: "Tallulah stays up all night every night and never gets up till five in the afternoon. She is a marvellous woman, and very amusing - but oh so exhausting!

"Two evenings with her would be enough to last you a lifetime."

Carter, 79, said that although there had been a lot of "static" in his family about making the collection public, he hoped people would learn more about his cousin.

"I'm the only one that tried to accumulate the stuff that related to Truman and put it in a scrapbook," he said.

The collection goes on display at Monroeville's Old Courthouse on 27 April, where it will sit alongside an exhibition of Harper Lee memorabilia.