London: A Nazi-looted painting that was hidden for decades has smashed expectations at a rare sale in London as investigators work painstakingly to identify the origins of hundreds of other works from the same haul.

Max Liebermann's "Two Riders on a Beach" was found among more than 1,200 works of art in the Munich apartment of German recluse Cornelius Gurlitt when police raided it in 2012, capturing global attention.