A painting found stashed inside a wall at an Italian museum has been confirmed as the stolen "Portrait of a Lady" by Austria's Gustav Klimt, prosecutors said on Friday, two decades after the artwork went missing.
The century-old painting was discovered concealed in an external wall by gardeners at the Ricci Oddi Gallery of Modern Art in Piacenza last month.
The museum estimates its could be worth between 60 and 100 million euros ($67-111 million).
"It is with no small emotion that I can tell you the work is authentic," Prosecutor Ornella Chicca told reporters.
Museum officials had initially said they could not immediately determine whether the painting was indeed the stolen Klimt until scientific tests were performed.
Painted in 1916-1917, the Expressionist work depicts the face and torso of a young woman with brown hair, over an emerald green background.
The painting went missing in February 1997 while the museum was closed for work.
In December, gardeners removing ivy from a wall found a small ventilation space and inside discovered the painting, without a frame and wrapped in a black garbage bag.
The ivy covering the space had not been cut back for almost a decade.
Chicca said further tests would determine whether the painting had been lingering inside the wall space ever since it was stolen, or whether it had been hidden there later.
Once those tests were complete, the painting will hopefully be returned to the gallery's walls, she said.
Art expert Guido Cauzzi studied the work under infrared and ultraviolet light, comparing images to those taken during tests performed in 1996.
"The correspondence between the images allowed us to determine that it's definitely the original painting," Cauzzi said.
The condition of the painting was "relatively good," he said.
"It's gone through a few ordeals, but only needs some routine care, nothing particularly complicated," Cauzzi added.
In 1996 it was determined through X-ray analysis that the painting covered up another, that of the face of a different woman.