Part of an exhibition displaying outfits and photographs of Marilyn Monroe was stolen while being transported to the Czech Republic from Italy, the event's curator said on Wednesday.
The exhibition, commemorating the 50th anniversary of her death, was created by the Museo Salvatore Ferragamo in Florence last year.
Ferragamo was the actress' favourite shoemaker and she owned a dozen pairs of his hand-made shoes.
Curator Jan Trestik said a truck carrying mannequins and photographs was raided in an apparently coordinated attack in the central Czech Republic on trucks carrying luxury goods from Italy.
David Sebek, spokesman for Prague Castle, which is due to host the show, said most of the exhibits, including her dresses, had already arrived intact.
Prague police spokesman Tomas Hulan said officers were investigating the case but refused to give any details.