Andy Clynes, a buildings site contract manager from Oldham, was overseeing a development at a mill near Manchester in 1999 when the papers were thrown out with other waste.

He took them out of the skip and stored the papers in a box in his loft for around 20 years until deciding recently to see what they are worth.

An auction house is now selling the highlight of the find, the sketches and designs for the Beatle’s so-called “magic” piano.

More of the papers from his find will go under the hammer in a separate sale later this year at Omega Auctions, with the total expected to fetch £10,000.