The Beatles star wrote a missive to Atlanta, Georgia DJ Paul Drew in May, 1966, and it wasn't until the radio jockey died in 2013 that his widow found the letter.

Los Angeles-based rock collectibles dealer Jeff Gold acquired the note and is asking for $20,000 (£12,500) for the item, which reveals previously unknown secrets about the Fab Four's recording days.

In the letter, Harrison writes that they were seriously considering recording at Memphis, Tennessee's iconic Stax studio with producer Jim Stewart, but the session never came to fruition.

He wrote, "We would all like it a lot, but too many people get insane with money ideas at the mention of the word 'Beatles,' and so it fell through!"

The involvement of Stewart is news to fans, as the Beatles' longtime producer George Martin was the only person they ever worked with until the end of the band's run in 1970.

In addition, Harrison details their time in the studio as they were in the early stages of recording Revolver.

He added, "The album we are making now should be out around October. But I hear Capitol will make an intermediate album with unused tracks from Rubber Soul, a few old singles and about two or three of the new tracks we have just cut... Well I am off to the studio any minute, as soon as John and Ringo arrive."