VIENNA (AP).- Rudolf Leopold, who assembled Austria's largest private art collection, including works allegedly stolen by the Nazis, died Tuesday at the age of 85.

Leopold died at a hospital in the Austrian capital after suffering multiple organ failure, said Klaus Pokorny, a spokesman for Vienna's famous Leopold Museum.

Leopold is credited with assembling the country's largest and most important private art collection that includes more than 5,000 works by artists such as Egon Schiele, Gustav Klimt and Oskar Kokoschka.

But the collection — which draws art aficionados from around the world — has been criticized in recent years by Austria's Jewish community and others who claim it contains works seized by the Nazis that should be returned to their rightful owners or heirs.

In 2008, a legal opinion commissioned by the Jewish community found that at least 11 of the foundation's works, including some by Schiele, Anton Romako and Albin Egger-Lienz, belonged to people who were persecuted by the Nazis — and that Leopold must have been aware, when he acquired them, of the possibility that they had been seized. Leopold, at the time, had disputed the allegations.

Born in Vienna on March 1, 1925, Leopold began collecting art in 1947 and soon became enamored by Schiele. Over the years, Leopold became known as an expert on paintings by the Austrian artist.

Austrian Chancellor Werner Faymann, in expressing his condolences, said Leopold succeeded in getting the Alpine republic's citizens to better appreciate Schiele's work.

"Leopold was one of Europe's most significant art collectors," Faymann said in a statement, adding that discussions about the origin of certain works should continue and be brought to a "dignified close."

Culture Minister Claudia Schmied, who has sought "clarity" regarding Leopold's collection, said Austria has lost a passionate collector and great personality of the art world.

He is survived by his wife, Elisabeth, and three children.

Funeral plans were not immediately announced.

Copyright © 2010 The Associated Press. All rights reserved.