'The one that got away' - a newly discovered Rothko at Christie's
April 13 2011

Christie's will offer a previously unknown painting by Mark Rothko on May 11th, proving that you can even make discoveries with modern art. 'Untitled No.17', painted in 1961, was bought directly from the artist, and had never been heard of or seen since:
“It’s one of the very few that got away,” said David Anfam, London-based art historian and the author of “Mark Rothko: The Works on Canvas.” “It went to a private collection soon after it was made and those collectors just kept a very low profile.”
The estimate is $18-22m. More here. Earlier this year, another newly discovered work by Andy Warhol made $17.4m. Sod finding lost Old Masters - I need to make find me one of these lost modern things.