A Russian court has imposed a hefty fine on the United States Library of Congress for not returning seven books more than twenty years overdue on their loan.
It says the library should pay $US50,000 for every day they are not returned.
The move intensifies a long-running dispute over the ownership of the books.
They are part of the Schneerson collection of Jewish texts which include editions of the Torah dating back to the sixteenth century.
The New-York based Hasidic Chabad-Lubavitch group says the entire collection, which is in Russian libraries, is part of its heritage.
