In the late 1960s Peggy Guggenheim handed over her 18th century Venetian palazzo and her extraordinary collection of 326 works of art to the Solomon Guggenheim Foundation, run by her cousin Harry in New York.

Now her descendants are launching a court appeal in France on Tuesday over how the collection is managed.

Spearheaded by her grandson Sandro Rumney, the plaintiffs complain that Peggy’s collection is not being shown in full, and is diluted by work from other sources. They believe the foundation is not adhering to the terms of her legacy.

According to AFP, the family hired bailiffs to analyse the displays, finding in 2013 that there were 94 pieces from the Guggenheim collection and 75 works from the Schulhof collection, put together by a couple of American art collectors.

This “breaks with the original arrangement that Peggy wanted and which should be respected after her death”.

This is the second time the family have filed a lawsuit against the Guggenheim Foundation. In 1996 they reached a settlement  that included an agreement from the foundation that they would keep the family more informed about their plans for the collection.

The Guggenheim Foundation has called the allegations “baseless”, and that it was “proud to have faithfully respected the wishes of Peggy Guggenheim for more than 30 years by keeping her collection intact”.