In 1988, Feliciano was working on an article for the Paris bureau of the Los Angeles Times about a stolen Murillo painting that had been bought by the Louvre, when someone mentioned that 20 percent of the looted art during World War II is still missing.

[1] During the Third Reich, agents acting on behalf of the ruling Nazi Party of Germany organized the spoliation of art of European countries.

[2] Informed by the original research of Lynn H. Nicholas, author of the ground-breaking book, The Rape of Europa: The Fate of Europe's Treasures in the Third Reich and World War II, Feliciano did additional research on the issue for his book in 1989, using – in addition to Nicholas' work – material from German looting inventories, documents that had been declassified and more than 200 interviews with art dealers, art historians and the surviving relatives of the families who were victimized.

[1] The French government ministries and museums refused to let Feliciano see their records and kept stalling until he was finally permitted to gain access through information requests lodged by the victims' families.

[3] The book points out also the role of Switzerland, whose legislation is very favourable to dishonest dealers and Russia, which categorically refuses to give back the stolen works of art found in Germany at the end of WW2 to their legitimate owners.

[1] The French government had to increase efforts to find original owners (or their heirs) of the nearly 2,000 looted works of arts stolen by Nazi Germany.

A Matisse painting titled "Oriental Woman Seated on Floor," was identified in the Seattle Art Museum as a piece that belonged to the heirs of Paul Rosenberg by someone who read the book.

The "Paysage" (pictured), a 1911 Cubist landscape by Albert Gleizes at the Pompidou Center was identified by Hector Feliciano as having been looted by the Nazis from the home of collector Alphonse Kann during World War II.

The three-judge lower court stated the following in reaching their decision:[9] The Lost Museum: the Nazi Conspiracy to Steal the World's Greatest Works of Art, as well as new documents presented to the court, the judges said that "Hector Feliciano had in his hands elements that permitted him to believe that Georges Wildenstein maintained direct and indirect relations with German authorities during the occupation."

[1] Feliciano worked as the director of the Ministry of Culture and the "Club des Poètes" in Paris before moving to New York City where he writes for El Pais and Clarin.