A long-running argument between the founder of Zurich’s iconic Le Corbusier museum is heading to court. Heidi Weber, a close collaborator, confidant, and friend of the legendary architect is suing the culture director of the city of Zurich Peter Haerle for defamation.

In 1964, Weber encouraged Le Corbusier to design a museum on Zurich’s lakefront and was granted a construction permit on the condition that she turn the building over to the city after 50 years. In 2016, two years after the 50-year term had expired, the city promptly renamed the Centre Le Corbusier Heidi Weber Museum to Pavillon Le Corbusier, enraging the elderly founder.

Compounding the disagreement are the terms under which Weber had to sell the building for CHF 1 million, although her son estimates the inflation-adjusted construction cost alone stands at CHF 18 million. The artistic value, he says, lies far higher—between CHF 45 million and CHF 70 million.