Medallion with the Bust of Christ ("The Cumberland Medallion"), from the Guelph Treasure, late 700s. This medallion may have originally served as a sacerdotal brooch and is the earliest object from the Guelph Treasure, the ecclesiastical treasure of Germany?s Braunschweig (Brunswick) Cathedral. Creator Unknown. (Photo by Heritage Arts/Heritage Images via Getty Images)

The heirs of a consortium of Jewish art dealers who sold the Guelph Treasure to the Prussian state at below market value in 1935 have appealed once again to a U.S. court after the long-running restitution case was dismissed in August 2022 due to lack of jurisdiction.

The heirs told a D.C. Circuit Court of Appeals on Tuesday that the sale had been made under the direction of Nazi leader Hermann Goering. They argued that this is not a domestic dispute and should be heard in a U.S. court because two of the dealers were Dutch nationals at the time while the others were effectively stateless since Hitler did not consider Jews to be legitimate German nationals.

The Guelph Treasure is made up of 82 Medieval-era devotional objects, including relics, crosses, altarpieces, and precious pieces in gold and silver, which could be worth as much as $250 million. It was sold to the state by Zacharias Hackenbroch, Isaac Rosenbaum, Saemy Rosenberg, and Julius Falk Goldschmidt for 10 percent less than they’d initially paid for it and is currently on display at the Museum of Decorative Arts in Berlin.

A bust reliquary of Saint Blaise from the Welfenschatz, or Guelph Treasure is pictured at the Kunstgewerbemuseum, or Museum of Decorative Arts, in Berlin. Photo by Tobias Schwarz/AFP via Getty Images.

A case for its restitution was first brought against the Stiftung Preussischer Kulturbesitz (SPK), an organization that oversees state-run museums in Germany, in 2008. The plaintiffs hit a roadblock in 2014, however, when a German commission argued that the low sale prices could be attributed to the Great Depression.

In 2015, the heirs took the case to the U.S, arguing that the forced transaction violated international law as an act of genocide. Ruled to be an “expropriation exception” to the 1976 Foreign Sovereign Immunities Act by the D.C. Circuit in 2017, it would therefore fall under the jurisdiction of U.S. law.

In 2021, however, the Supreme Court ruled unanimously that the suit should not be filed in a U.S. court and the case was again dismissed by senior U.S. district judge Colleen Kollar-Kotelly in August 2022. The heirs failed to convince her that their ancestors were foreign nationals at the time of the sale, which would render the transaction a violation of the international “domestic takings” law, in part because they had not made the same case in previous filings.

In their new appeal, the heirs have doubled down on the argument that the dealers were not German nationals. In a brief, the SPK stated, “plaintiffs forfeited these alternative arguments years ago. Regardless of whether their complaint’s allegations could support these arguments, litigants must do more than gesture at possible legal theories with vague allegations.”

In court, the SPK’s attorney Jonathan Freiman added that the Guelph Treasure was technically owned by the dealers’ German companies, which were based in Frankfurt.

The panel of three judges have not yet indicated when a decision will be announced.