The New York Times website runs this story from an International Herald Tribune special art market section that tells the story of a provincial auctioneer assigned the task of creating an inventory of a dentist’s estate for his heir. In the apartment, Osenat found stolid furniture but some serious paintings by Bonnard and Vlaminck:

When he descended into the basement, Mr. Osenat discovered, neatly stacked in their original packaging and concealed under dusty piles of discarded rags, some 20 works by master painters of the postwar era.

“It was an incredible find. When a single work by Mitchell appears on the market, it usually makes the cover of any sale catalogue,” Mr. Osenat said during an interview, referring to the American Abstract Expressionist painter Joan Mitchell. “We have four large Joan Mitchells; the rest are works not seen on the market in 60 years.”

On June 14, “The Estate of Doctor B” will go under the hammer at Osenat Fontainebleau, Mr. Osenat’s saleroom near the Château de Fontainebleau, the 16th-century royal residence built by the renaissance king François I, about 60 kilometers, or 37 miles, southeast of Paris. For privacy reasons, the heir, a surviving daughter, has wished not to reveal her or her parents’ name.

Beside the four oil paintings by Ms. Mitchell, the sale will offer 19 works by other major 20th-century and postwar artists, including Nicolas de Staël, Sam Francis, Jean-Paul Riopelle, Georges Mathieu, André Lanskoy and Alfred Manessier, alongside more classic works, including the Vlaminck.

“This collection, rare in its quality, is extremely well preserved,” said Michel Maket, expert for the sale and a specialist in late 19th- and 20th-century paintings in Paris. “Dr. B was a private person who did not show his collection.”

Estate Yields Works by Postwar Masters (New York Times)