Austria, the Albertina Museum and the Leopold Museum Foundation have answered the US government and two senators in a New York court, arguing that the amended federal law on Nazi-looted art reaches beyond what Congress may do. The response, filed on Friday, takes on briefs the Justice Department and Senators Richard Blumenthal and John Cornyn submitted in September, and repeats the claim that the revised Holocaust Expropriated Art Recovery Act breaches Article III of the Constitution and the Tenth Amendment.

The case concerns works by Egon Schiele claimed by Timothy Reif, a descendant of the Viennese cabaret performer and collector Fritz Grünbaum, who died at Dachau in 1941. Reif says the pictures were taken when the Nazis seized his ancestor's collection; the museums counter that the works left Austria lawfully in the 1930s through Grünbaum's sister-in-law and were sold on to a Swiss dealer in the 1950s. The museums had already challenged the law in earlier motions; this filing answers the new arguments the government and the senators put forward, in a brief filed on 18 September.

The dispute turns on changes made to the HEAR Act in 2025. Passed in 2016, the act now runs indefinitely, and the amendments removed defences that had let courts throw out claims on technical grounds, including differing state time limits and laches, which bars claims brought after unreasonable delay. The Austrian side argues the law falls short of creating a single federal restitution regime, leaving the substance to state law, while telling courts how they must decide — an intrusion, in its view, on judicial power and on powers reserved to the states.

The defendants' lawyer, William L. Charron, said the filing was a direct answer to the fresh arguments for the law's validity. He added the case could be resolved without deciding the constitutional question, but if a court had to rule on it, the matter could eventually reach the Supreme Court. The filing decides nothing itself, but it frames a constitutional test that could narrow the main federal route families use to pursue looted art in American courts.