Monet's Nympheas fetched $22.5m (�15.6m) in 1999

The painting of a sunny Sunday afternoon in a Paris park - Au Parc Monceau - was once owned by a Jewish family who were forced by the Nazis to sell the painting.

It had belonged to Ludwig Kainer, a painter, illustrator and set designer who worked for the Ballet Russes and the Berlin opera, before one of a number of "Jew auctions".

Having discovered the provenance of the work its owner has agreed to share the proceeds of its sale with Kainer's descendants.

"There's a lot more information that's now available in terms of archives and looking up old auction catalogues from the 1930s that one might not necessarily have had access to 10 years ago," said Helena Newman of Sotheby's.

Star lot

"So from the point of view of the heirs it's very fortunate that this painting has come to light now," she added.

Matin�e sur la Seine, 1896, shows Epte and Seine rivers

"There's a bit more Monet around than you'd expect because he's so expensive that museums can't afford to buy him, so there's quite a lot of splendid pictures still washing about in private hands," said Mr Barker.

Claude Oscar Monet was a painter who intently studied the fleeting effects of light on the natural world.

He was born in Paris on 14 November 1840, but spent most of his childhood in Le Havre, Northern France.

It was a feature of his work that he would paint a particular subject in a variety of weather conditions or times of day or year.

He famously did this with the waterlilies in his garden at Giverny, the Haystacks, Rouen cathedral and even the Houses of Parliament in London.

His Haystacks were painted between 1890-1891 and the series of 23 canvases are now recognised as one of the most important landmarks in modern art.

Monet's painting Impression, Sunrise also gave the Impressionists their name and earned Monet his "father of the impressionists" title.