BERLIN -- Is it Mozart? A mysterious portrait discovered in a Berlin vault could be the last image of the musical genius painted while he was alive, but experts are at odds over its authenticity.

Despite the doubts, the painting, entitled Gentleman in Green Coat, is to go on show in Salzburg soon as part of Austria's year-long celebrations of the 250th anniversary of the composer's birth.

If it is in fact Mozart, the portrait would show the premature aging of a bon vivant who died when he was only 35.

The face is lined, the hair is graying and the tired features speak to a lifetime of experience. The man is smiling but without great conviction.

Something about the impressive mane, the intelligence in the gaze and the nonchalance of the pose prompt the viewer to think that the model was not just anyone.

Yet the subject appears banally human, with slouching shoulders, rings under his eyes and the start of a double chin.

Perhaps it is Mozart, but if so it is an image that dramatically corrects the angelic figure familiar from the half dozen portraits judged to be authentic.

It meshes, however, with the biographical details known from the end of his short life, in which his body was ravaged by excesses with alcohol and women. The swollen face in the painting, for example, could easily reflect treatment for syphilis, from which Mozart is widely believed to have suffered.

The picture, signed by a renowned portraitist of the era, Johann Georg Edlinger, was completed in 1790 in Munich, where the composer spent a brief period a year before his death.

While he stayed in the Bavarian capital, he frequented The Black Eagle inn, whose patron was a friend of the artist.

The Gentleman in Green Coat remained in Munich for a century and a half before Berlin's Gemaeldegalerie museum bought it from an art dealer in 1934.

But the painting remained in a depot in eastern Berlin during World War II and Germany's four-decade-long division until it went on display again last year.

"There is no reason to doubt it is Mozart," museum director Wolf Lindemann said, although "definitive proof" will never be possible.

A descendant of the painter, Wolfgang Seiller, was the one who drew the link to Mozart by comparing the physical traits of the model with those of another portrait of the composer in a similar pose on display in Bologna, Italy.

The historical archives in Munich, however, offer several pieces of evidence that cast doubts on Berlin's claims.

If Mozart were the model, the painting would have somehow made reference to music as a form of "recognition of his art by the German royal courts", the city wrote in a report on the painting.

Secondly, historical records indicate that Mozart only spent a week in Munich in the autumn of 1790, where he gave a concert for the Neapolitan king.

Skeptics say that it would have been difficult for him to find the time to pose for a painter known for interminable sittings.

The city of Munich also argues that a known portrait of Mozart would surely have been put on display in the months following his death on December 5, 1791.

And finally, the painting is part of a set with a female portrait, yet Mozart's wife Constanze was not in Munich at the time.

Mozart might have had himself secretly painted with a favorite mistress but in those days, "even the greatest libertine would not have gone that far", said the director of the Munich archives, Richard Bauer.

Bauer, who said that the Gentleman in Green Coat is far more likely to be a wealthy merchant, noted that "subjective physical similarities that are not backed up with other indices have never been enough to identify people. Not under the law, and not in the history of art."