The correspondence was recently discovered in a record collection stored in the anonymous owner's attic.

It is a version of a famous note Lennon wrote to the Queen in 1969 informing her he wished to return the Member of the Most Excellent Order of the British Empire (MBE) medal he received in 1965.

The owner reportedly bought the records containing the letter for $12.20 (£10) at a car boot sale two decades ago, but only had it valued at a Beatles memorabilia event in Liverpool, England on Wednesday (26Oct16).

Darren Julien of Julien's Auctions, who valued the letter at $73,500 (£60,000), tells the Liverpool Echo newspaper, "We'll be doing some further research but this could be the Beatles find of the year. There is no doubt that the handwriting is definitely that of John Lennon."

The near-identical note Lennon sent to the monarch is kept in Britain's Royal Archive, and Julien believes this one is an early draft the rocker never sent.

"You can quite clearly see that the signature in this letter has been smudged," he explains. "My theory is that John Lennon never sent this draft because of the smeared ink.

"If you're writing to the Queen, you want the letter to look pretty perfect, you don't want the ink to be smudged. This suggests that he wrote a second version of the letter, which was the one that was actually sent to the Queen."

The letter outlines Lennon's reasons for returning his MBE, which included British military involvement in the 1967-70 Nigerian Civil War, the country's support of U.S. troops in Vietnam, and jokingly, the chart fall of his solo hit Cold Turkey.

The late rock legend received the honour alongside his Beatles bandmates Paul MCCartney, George Harrison and Ringo Starr at London's Buckingham Palace in 1965.