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National Geographic , Pascal Cotte
Art collector Peter Silverman examines the "La Bella Principessa" artwork. "Mystery of a Masterpiece" reviews the entire process of authenticating artworks.

When a 13-by-9-inch portrait of a young girl sold at the Christie's auction house for $20,000 in 1998, it was attributed to a 19th-century German artist.

But carbon-data tests reveal that the vellum canvas is much older, from the Renaissance era of the 15th century. And the drawing could be an undiscovered Leonardo da Vinci masterwork worth at least $150 million.

In the PBS documentary "NOVA: Mystery of a Masterpiece," airing Wednesday, Jan. 25, at 8 p.m. on KUED, the ink and colored chalk work is carefully scrutinized by art experts and forensic investigators to authenticate that the portrait is "the real thing" — a Leonardo masterpiece.

"Mystery of a Masterpiece" is an informative examination of the entire process of authenticating artworks.

The documentary also includes a discussion of the multibillion-dollar criminal market in fraudulent art and an examination of how forgeries are created.

Leo Stevenson, a real-life Neal Caffrey from USA Network's "White Collar," is shown re-creating Monet's "Haystacks" painting in his New York studio.

With no clear provenance — a trail of invoices, catalog listings or other records that would allow a work to be traced back to an artist — Canadian-born art collector Peter Silverman, who bought the presumed Leonardo drawing for a Swiss collector, identifies that three puzzle pieces must be in place.

Before it can be proved that the work, now named "La Bella Principessa," is truly by Leonardo, it must be reviewed artistically, historically and scientifically.

One of Silverman's first stops is the Luminere Technology laboratory in Paris.

"When I first looked at the portrait, there was such quality," Lumiere's Jean Penicault says. "You could tell it was something totally special."

Penicault uses a revolutionary "multispectral camera" that can capture light from frequencies beyond the visible light range, allowing the extraction of information that the human eye fails to capture.

"Significant" stylistic parallels are found when compared to other Leonardo works, and it is revealed that the drawing was made by a left-handed artist, as Leonardo is known to have been.

To establish its historical merits, the subject of the work must be identified.

Martin Kemp, emeritus professor of the history of art at Oxford University, believes that the profile portrait could be of Bianca Sforza, the daughter of Ludovico Sforza, duke of Milan from 1452-1508, and his mistress, Bernardina de Corradis.

But Leonardo scholars continue to be divided that the work is by the Renaissance master, as the documentary details through various interviews.

"Mystery of a Masterpiece" makes no definitive conclusion that "La Bella Principessa" is a Leonardo work, but that mystery makes the documentary that much more intriguing.

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