The Polska daily newspaper reported that numerous Mozart scores are believed to be kept in the archives of the Jasna Gora Monastery.
Located in Czestochowa, the monastery is the national shrine of Poland and the third-largest Catholic pilgrimage site in the world, Poland Radio noted.
Its archives are home to more than 3,000 hand-written historic music scores, two-thirds of which have been performed by the monastery's orchestra.
Eighteen scores that appear to be signed by Mozart are now being examined for authenticity, Poland Radio said.
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