She looks unfazed – not a bit like a woman who's been missing nearly 23 years. But Italian authorities claimed Friday they'd authenticated the stolen "Portrait of a Lady," painted by Austrian master Gustav Klimt.

Gustav Klimt's "Portrait of a Lady" vanished from an Italian art gallery 23 years ago - and then just as mysteriously turned up last month, hidden within the gallery's walls. CBS News

As art mysteries go, how good is this? "Well, it's stuff upon which mini-series are made, right?" said art historian Liz Lev. She said the decades-long real-life-drama puzzled investigators – and, quite possibly, thieves: "It's a distinctive Klimt style, so you sort of take it down to the local pawn shop: 'Hey, I've gotta get rid of this.' Someone's gonna go, 'Hmmmmmmm.'"

The portrait was reported missing from an Italian gallery in 1997. Then, this December, police were called to the gallery grounds, after a gardener who'd been clearing ivy discovered a hole in the wall – and, unbelievably, the painting.

"The painting is in very good condition," Lev told correspondent Seth Doane. "The first thing they check was, 'Oh my gosh, if that's been sitting outside in rainy, cold Piacenza for the past 23 years, what condition will it been in?' But it's actually in good condition, which indicates that it was probably taken away and then returned."

Investigators plan to do more tests on this Klimt, which is actually two portraits, one painted on top of another – a uniqueness which helped prove it was the real thing.

In the 1990s art experts examined Klimt's "Portrait of a Lady" and discovered that the artist had painted over an earlier portrait. An X-ray of the recovered painting revealed it to be the same. CBS News

Klimt worked mainly in Vienna in the early 1900s. He may be best known for "The Kiss" – and, as Morley Safer noted in 2008, his seductive portraits of socialites: "They're slender and elegant creatures," said Renee Price, director of New York's Neue Galerie.

"Who happen to have no clothes on," Safer said.

"Just an accident," she laughed.

You've probably seen, worn or sipped from a Klimt-patterned-something. "You'll see this beautiful umbrella – 'What a pretty pattern!' 'Oh, it's Klimt!'" said Lev. "You'll be looking at someone's golden scarf – 'Oh, that's pretty.' 'Oh, it's Klimt!' It's everywhere!"

The recovered masterpiece is under lock and key, hidden away with its secrets: How is it in such good shape? And where has it been?

Like any good mystery, there's a cliffhanger.



Story produced by Mikaela Bufano.