Italian magistrates on Sunday opened an inquiry into the causes of a fire that gutted an aristocrat's library in the southern city of Cosenza on Saturday, killing three people living in an adjacent apartment and destroying ‘priceless’ works by the Renaissance philosopher Bernardino Telesio and letters to Galileo Galilei, judicial sources said.

The leading Corriere della Sera newspaper described the private museum housing the collection of the Bilotti Ruggi D'aragona family as "the most important library in southern Italy."

The owner of the library and well-known collector, Roberto Bilotti, said he had informed local authorities repeatedly about the risk posed by the three mentally handicapped squatters living in the apartment below the library where the fire started.