George Harrison's amplifier used by during recording sessions for The Beatles albums Revolver and Sgt Pepper's Lonely Hearts Club Band is set to sell for £70,000.
The rare Vox UL730 amplifier will go under the hammer when after being rediscovered by accident after it was borrowed by former New Order bassist Peter Hook for a recording session reports metro.co.uk.
An engineer only discovered it used to belong to the musician, whose name was scratched inside, when he was called in to fix it after it broke down.
Researchers then tracked down the amp's history and found a photograph of Harrison using it.
The amp is expected to fetch between £50,000 to £70,000 when it is auctioned off on Thursday, December 15 at Bonhams in Knightsbridge, London.
Stephen Maycock, Bonhams entertainment memorabilia consultant, said: 'Very few amps used by the Beatles have come to auction before, and to find one that was used on two such significant albums is truly rare and exciting. Beatles fans all over the world will be eager to own such an important piece of music history.'
Harrison died aged 58 of cancer ten years ago on November 29, 2001.
A close pal of Eric Clapton's, Harrison was the lead guitarist for The Beatles alongside John Lennon, Paul McCartney and Ringo Starr.