Lennon penned a letter titled 'A Matter Of Pee' in the 70s and it was sold by London auction house Cooper Owen to a private collector, reported Daily Express.
The Beatles star penned the letter to complain about Keith Moon of The Who and singer-songwriter Harry Nilsson urinating on the studio mixing desk and claimed he left the studio before the incident.
Lennon was shot by Mark David Chapman in New York City on December 8, 1980 when he returned from Record Plant Studio with his wife, Yoko Ono.