Basquiat's sisters file $1 million lawsuit against Christies Auction NY for plans to sell phony work by their now legend brother. by Traver Dodorye

Two siblings of the late modern art superstar Jean-Michel Basquiat claim Christie's auction house is on the verge of selling what may be phony works by their brother.

In a $1 million false endorsement and false advertising lawsuit filed Tuesday in Manhattan Federal Court, Jeanine Basquiat Heriveaux and Lisan Basquiat say Christie's has failed to verify many of the roughly 50 pieces on sale this month.

The plaintiffs, who administer their famous brother's estate, claim Christie's presented the estate's authentication committee in 2007 with just seven pieces. Of those, the estate declined to sign off on one as the real deal.

"The remainder of the catalog items were not only not authenticated by the authentication committee … but also were never submitted to them for review," the plaintiffs say.

The auction house, which claims the pieces are a collection that once belonged to former Basquiat lover Alexis Adler, failed to submit the works to the estate for review because it knew or had reason to believe many of the items were fake, the suit alleges.

The plaintiffs maintain that "an average person could see that the printing on the (items) was done by a number of different individuals."

Despite bypassing the authentication committee, Christie's included a notice with its catalog for the works promising that the pieces had been copyrighted by the estate, the suit claims.

"Christie's included the misleading notice to increase the auction prices … and to maximize Christie's income from their sales," the suit alleges.

The plaintiffs are seeking at least $1 million in damages and a court order barring Christie's from using the estate's name in the sale.

Since his death in 1988 of a heroin overdose at age 27, Basquiat’s artworks have sold at auction for as much as $48 million. The artist got his start spray-painting graffiti on walls in SoHo.

“Hopefully, this action will put Christie's and the art world in general on notice that the rights of the Estate of Jean-Michel Basquiat must be respected,” said the Basquaits lawyer James Cinque.

The auction house didn't immediately return a request for comment.

The three major pieces in the collection are "a glyph-like work on plaster that reads "Olive Oyl," a door with the phrase "Famous Negro Athletes" and a radiator with the word "Milk" painted on it.

"Jean was just a young and wonderful person. ... Everything around us was about art at that time," Adler recalls in a Christie's press release for the sale.

"Today young people are willing to learn more about Jean and are really interested in his art. I'm really excited to be able to have the show at Christie's ... and share the artwork with other people so they can enjoy it. I've been enjoying it for a long time."