The London Jewish Museum of Art - the Ben Uri Gallery - has bought a rare Marc Chagall painting for a fraction of its value after spotting it in a Paris auction.

The museum, based in St John’s Wood, London, secretly bought the 1945 work Apocalypse in Lilac, Capriccio, which had been previously unknown to collectors, for £26,600.

It was spotted by the museum’s chairman, David Glasser, in a catalogue published by Tajan, a leading French auction house.

The painting is one of a small group of images Chagall painted in response to the Holocaust, when he began to hear of the Nazi atrocities after he and his wife fled France in 1941.

The watercolour features a naked image of Christ on the cross screaming at a Nazi storm trooper.

Chagall regularly used a crucifix as a symbol for Jewish persecution, but this new painting is seen as one of his darkest works, with figures in the background being tortured by Nazi troops.

Mr Glasser applied to the Art Fund, which helps British galleries acquire paintings for funding, who agreed to put up €100, 000.

But due to a poorly-attended sale in late October , which did not include bidders from major galleries, the painting was bought for just €30,000.

The gallery kept the purchase secret until the painting could be shipped to the UK, as Mr Glasser feared the French authorities might refuse to grant an export licence.

The work will be unveiled at the Osbourne Samuel gallery in Mayfair this week, and will later be moved to the Ben Uri permanent collection.