£13 million for Monet waterlilies

A monet watercolour which has been hidden from view for 77 years has been sold for just over £13 million.

An anonymous private buyer snapped up the painting - the most expensive sold in London this year - called Nympheas, a t Sotheby's. Experts had expected the painting to fetch more than £10 million because it is in Monet's waterlilies series and because it was new on the market.

The painting, which was completed in 1906, was last seen in public in 1925 and has been kept as part of a French family collection having been bought from Monet's dealer Durant-Ruel in 1940.

The painting has never been reproduced in colour and collectors had been eagerly awaiting its re-emergence in public for some time. John House, of the Courtauld Institute of Art, said: "It's very rare to see a picture in such wonderful condition. This is the way Monet wanted them to look, it's very fresh, very matt, and not varnished."

Bids for the painting started at £6 million last night and increased at £500,000 a time as a tussle developed between two mystery telephone bidders.

The most expensive Monet painting is the Bassin aux Nympheas et Sentier au Bord de L'eau, which went for £19 million in 1998.