No amount of expertise helped: the renowned New York Pace Gallery seems to have fallen for a not even particularly sophisticated scam.
A man named Jean-Pierre Seurat is said to have led her to believe that he was a grandson of Georges Seurat and had a drawing of the same for sale.
"Le Suiveur" (The Pursuer) shows two shadowy figures in front of a lighted window.
In November, Pace apparently paid two million dollars before it became apparent that the French artist, who died in 1891, had no children and therefore no grandchildren.
On his homepage, Jean-Pierre Seurat tried to excuse himself as the pointillist's “distant cousin”.
But by then it was already too late: the gallery had the authenticity of the drawing checked more thoroughly – with a negative result.
Pace is now suing the state Supreme Court against the alleged fraudster and possible accomplices.
Also involved in the case is Constance H. Schwartz, formerly director of the Nassau County Museum of Art in Roslyn Harbor on Long Island.
She is said to have approached Pace and made contact with the alleged Seurat grandson.
Incidentally, he is not supposed to be related to the artist.
According to the indictment, Schwartz lured the gallery with the prospect of further "masterpieces" belonging to the alleged descendant.
In addition, the intermediary is said to have sent the art dealer a forged certificate of authenticity.
A family-owned work that has never been shown publicly?
Pace was supposed to be persuaded with documents that referred to Félix Fénéon, the French art critic and collector who coined the term Neo-Impressionism.
In addition to Seurat, Fénéon, who died in 1944, also made Henri Matisse and Camille Pissarro better known.
Two years ago, the New York Museum of Modern Art dedicated an exhibition to him.
An alleged note from Fénéon's granddaughter is said to have served Pace as proof that the drawing was an heirloom.
The sheet was never shown publicly and has always been in the family's possession - which probably made it attractive for the gallery, which now has to deal with the public embarrassment.
Paintings by Seurat have fetched around $34 million at auction, and now Pace has been accused of neglecting the prospect of high returns by the gallery.
Pace blames the alleged fraudster for the mess: He contributed to the fact that the trust between buyers, collectors and the public, which is fundamental to the art market, suffered severe damage, according to the complaint.