An installation made up of artificial dung, intended to pay tribute to a seminal work seized by the Nazis in 1937, has gone on display in Berlin.

Martin Gostner's work, The Oriel of the Blue Horses, features four piles of fake blue manure.

Each pile corresponds to one of the horses in Franz Marc's seminal work The Tower of Blue Horses.

The expressionist masterpiece was branded "un-German" by the Nazis and has never been found.