Vienna's Musikverein is investigating a series of note sheets that bear the composer's name. The concert hall did not reveal where the sheets were found.
Otto Biba, the archive director of the Society of Musical Friends of Vienna, said on state television that there was as yet no verdict on the work's authenticity. "Some things are for it and some against it," he said.
He added that the discovery of the work had nothing to do with the upcoming countrywide celebration of Mozart's 250th birthday, saying, "This is in no way a gag for Mozart year."