Previously unknown artworks by masters including Marc Chagall, Otto Dix, Max Liebermann and Henri Matisse are among those found inside a flat in Munich.
Prosecutors said the issue of ownership was still to be clarified. The total value has been estimated at about €1billion (£846 million).
Other artists whose works were found include Pablo Picasso and Henri de Toulouse-Lautrec, as well as Canaletto and Gustave Courbet.
More top news
Rain will slowly edge into Scotland, reaching Northern Ireland by Thursday afternoon. There will be plenty of cloud across the UK.
Clashes between rival supporters marred West Ham's EFL Cup fourth round win over Chelsea at the former Olympic Stadium
Jane Beedle, Andrew Smyth, and Candice Brown went head-to-head in a closely contested royal themed final.