The country's most important art collector, Leopold founded the museum of the same name in 2001, exhibiting prized works by such famed Austrian artists as Gustav Klimt and Oskar Kokoschka, and the largest collection of Egon Schiele paintings and sketches in the world.
However, he also came under fire over the origins of some of his paintings, which critics said had been stolen by the Nazis from their previous Jewish owners.
Although Austria passed legislation on the restitution of looted art in 1998, the Leopold Museum -- a private foundation -- managed to avoid returning any paintings and its founder, widely acknowledged as one of the world's main Schiele experts, always denied knowingly acquiring stolen Jewish objects.
Leopold opposed any restitutions, preferring to offer compensation instead, even after an independent commission investigated the provenance of 23 disputed paintings from the Leopold Museum's collection last year.
Born in 1925 in Vienna, Leopold first studied medicine after World War II.
He started collecting paintings and other artworks as early as 1947, focusing at first on the old masters and on 19th-century art, before he became acquainted with Schiele's work in 1950.
Five years later, he organised an exhibit on contemporary Austrian art in Amsterdam, with a selection of works by Schiele, that attracted international attention.
By the 1990s, his collection counted some 5,000 works of art and was estimated to be worth 7.9 billion schilling (574 million euros, 884 million dollars).
He died Tuesday morning in a Vienna hospital, according to the museum.http://www.france24.com/en/20100629-austrian-art-collector-rudolf-leopold-dies