A painting found stashed inside a wall at an Italian museum has been confirmed as the stolen "Portrait of a Woman" by Austria's Gustav Klimt, prosecutors said on Friday, two decades after it went missing. "It is with no small emotion that I can tell you the work is authentic," Prosecutor Ornella Chicca told reporters, referring to the painting discovered last month by gardeners last month inside an external wall at the Ricci Oddi Gallery of Modern Art in Piacenza. gg-ams/klm