NEW YORK (The Associated Press)—The owner of a silkscreen self-portrait of Andy Warhol is suing the late artist's estate, saying it conspired for 20 years to control the market for Warhol's work with authority to stamp "DENIED" on any work it claimed was fake.

In a $20 million lawsuit filed Monday in U.S. District Court, Joe Simon-Whelan said the Andy Warhol Foundation for the Visual Arts Inc. and the Andy Warhol Art Authentication Board forced owners of each Warhol work to sign contracts giving them a "perpetual veto right over its authenticity."

He accused them of engaging in a two-decade scheme of fraud, collusion and manipulation that caused them to twice deny the authenticity of his 24-by-20-inch silkscreen even though it already had been authenticated multiple times by the estate or its related entities.

As a result, the lawsuit says, anyone who buys a Warhol painting that has been authenticated by the board risks having the authenticity revoked at any time.

Simon-Whelan, a U.S. film writer and producer who lives in London, accused the foundation and the board of providing "a facade of corporate credibility obscuring a deeply corrupt enterprise that enables defendants to benefit from Warhol's art and reputation."

He said they had adopted a policy of rejecting as many works as possible to induce artificial scarcity in the market for Warhol's creations.

The foundation's chief financial officer, K.C. Maurer, said she had not seen the lawsuit and couldn't comment. A telephone message left with the authentication board was not returned.

Simon-Whelan said he bought the silkscreen, called “Double Denied” in his court papers, for $195,000 in 1989, two years after Warhol died.

The work was one of several created in 1964 at Warhol's direction from an acetate personally created and chosen by him, the lawsuit said. It was going to be sold in December 2001 for $2 million until the authentication board without explanation stamped "DENIED" on the back of it in red ink, which bled through to the front, according to the lawsuit.

Simon-Whelan said he submitted it a second time in 2003 only to get rejected again.

The lawsuit said “Double Denied” is one of a small series of paintings created by Warhol so he could exchange them for rare and expensive video cameras, video recorders and other equipment that could be used in his filmmaking.