A jubilant Ben Uri Gallery was celebrating its latest acquisition this week: an important work by the distinguished German artist George Grosz, which in brutal clarity shows the horrors of the Second World War.

Grosz, who was not Jewish, and died in 1959, painted Interrogation - a man being tortured by Nazi soldiers - between 1936 and 1939, following his emigration to the USA in 1933.

There are only 15 examples of Grosz's work on public view in the UK, just six of which are in London.

The Ben Uri bought the watercolour with the aid of the Art Fund, together with support from the MLA/V&A Purchase Grant Fund, the Montgomery Gallery in San Francisco, and private donors.

The painting will be included in the Ben Uri's Holocaust Learning Pack as part of its Art in the Open programme.