The Art Looting Investigation Unit (ALIU) was a special intelligence unit during World War II whose mission was to gather information and write reports about Nazi art looting networks. Composed of only a few handpicked men, the small unit conducted interrogations and investigations in Europe starting in 1944 and focusing mainly on Germany, France, the Netherlands, Switzerland, Italy, Spain and Portugal. Their mission was different from but related to that of the Monuments Men. After the war, the reports the ALIU wrote were marked secret and forgotten for many years until the late 1990s when they began to be declassified . The reports remain an important source for research into the history of the origin of works of art (provenance research) and for the restitution of looted art from the Nazi era. Source: Wikipedia (en)