Exhibition queries provenance of Marcel Duchamp urinal
It is regarded as one of the most important artworks of the 20th century.
The urinal displayed in an exhibition in New York in 1917 - is recognised as the first piece of conceptual art.
But a new exhibition in Edinburgh claims the work was not made by Marcel Duchamp but by a little-known female artist.
BBC Scotland art correspondent Pauline McLean reports from Edinburgh.