Britain's leading galleries may have to return some works of art after publishing a list of 350 paintings of whose origin they admit they are uncertain.

The list includes works by well-known artists such as Picasso, Renoir and Cézanne, and all have gaps in their history between 1933 and 1945 – the period when the Nazis were looting artworks across Europe.

The list of 350 paintings was published by the British National Museums' Directors' Conference earlier this year. Of the paintings on the list, 130 are held at the National Gallery and more than 80 at the Tate. The British Museum has 11 of the artworks listed.

Tate Gallery director Sir Nicholas Serota said that the inclusion of a painting in the list did not mean it had been stolen.
- The Art Loss Register continues to investigate the loss of a Dutch Old Master oil painting (left).

River Landscape, by Matthys Schoevaerdts, disappeared during the European Fine Art Fair at Maastrict, Holland, in March 1997.