In the latest chapter of a more than 20-year-old legal dispute, Barcelona is suing four women for the return of paintings left to the city by their father, the late, exiled Spanish cotton baron and art collector Julio Muñoz Ramonet, the Telegraph reports.

Upon his death at 79 in 1991, Ramonet bequeathed his mansion and art collection to Barcelona, rather than to his daughters, Carmen, Isabel, Alejandra, and Helena. The quartet have been contesting the terms of the will ever since.

In July, a Supreme Court ruling ordered the women to turn over the mansion and all its furnishings to Barcelona. When city authorities entered the premises, they found that the collection’s most prized paintings were nowhere to be found (as previously reported by artnet). Following a careful inventorying of the grounds, the city has accused the sisters of stealing the missing works.

Two paintings have been recovered to date: El Greco‘s The Annunciation, and The Appearance of Our Lady of the Pilar by Francisco Goya. They were found in private home in Alicante, where they were being offered for sale.

Estimated to be worth tens of millions of euros, the collection features Old Masters such as Velazquez, Botticelli, and Rembrandt.