Ian Horne, a sound engineer who worked with Sir Paul McCartney after he left The Beatles, has led the hunt for the stolen Hofner violin bass, which McCartney bought in 1961 and remained in his collection after the band split up. Horne found the instrument locked in a van near London's Ladbroke Grove, where McCartney had stored it. He returned the next day to find the padlock on the floor, and informed McCartney about the loss. The search for the instrument is featured in the documentary McCartney: The Hunt for the Lost Bass, available on BBC iPlayer.