At the time of the purchase, the Weldons had spent several decades amassing a robust collection of Dutch and Flemish masters. Their collection was exhibited at the Walters Art Gallery in Baltimore in 1999. The catalog for the exhibition said the Coorte painting of chestnuts had come from a private collection in the Netherlands and had been shown through Mr. Koetser’s gallery in Zurich, but it did not mention the Meissners or the sale by Christie’s.
Mr. Bischof said he tracked the painting to Mrs. Weldon in 2011 and sent her a letter detailing the Stasi raid, the arrest of Helmuth Meissner, and Mr. Meissner’s confinement within a psychiatric facility, which a German state commission in 1997 called “a clear case of abuse.”
Mr. Bischof also traced for her what he said was the route the Coorte took after falling into Stasi hands. “We hope we can resolve this matter amicably and in an atmosphere of mutual trust and can avoid a bitter and lengthy dispute,” he wrote.
When the negotiations broke down, Mrs. Weldon’s lawyer, Mr. Costantini, filed the legal action in Munich, where Konrad Meissner lives, asking a judge to affirm her ownership and asserting in court papers that nothing presented so far establishes Konrad Meissner’s ownership and that Mr. Meissner “bases his claims on legally incorrect points of view.” Mr. Costantini said Mrs. Weldon’s heirs plan to continue the legal battle to retain the Coorte.
In his brief, Mr. Costantini suggested that perhaps the Meissner chestnuts painting simply resembles a different one in Mrs. Weldon’s collection. But the 2008 catalogue raisonné of Coorte’s paintings, by Quentin Buvelot, which is intended to be a full inventory of his works, does not list any other painting that features four chestnuts and is dated to 1705.
Mr. Meissner, 76, said he is sure the Weldon painting is the one he grew up with. “It is hard not to recall your parents had this work on the wall,” he said, “when you looked at it every day.”