3 lifelong Beatles fans seek to find missing Paul McCartney guitar and solve "greatest mystery in rock and roll"

A guitar expert and two journalists have launched a global hunt for a missing bass guitar owned by Paul McCartney, bidding to solve what they brand "the greatest mystery in rock and roll."

The three lifelong Beatles fans are searching for McCartney's original Höfner bass — last seen in London in 1969 — in order to reunite the instrument with the former Fab Four frontman.

McCartney played the instrument throughout the 1960s, including at Hamburg, Germany's Top Ten Club, at the Cavern Club in Liverpool, England and on early Beatles recordings at London's Abbey Road studios.