The notes, which were sent in 1959, refer to Pussy Galore, a character form the author's novel Goldfinger, and answer a query about the book's cliffhanger ending.

Fleming's 1959 novel depicted Galore as the head of an all-lesbian criminal gang who aids villainous madman Auric Goldfinger, and in one of the letters, the writer describes her sexuality as a "psycho-pathological malady" which could be cured by the "right man".

Bosses at Bonhams auction house in London, where the letters will go on sale later this month (Nov15), estimate they will sell for between $4,800 (£3,000) and $6,400 (£4,000) each.

In the 1964 movie version of Goldfinger, Galore was played by Honor Blackman.