Last summer the director of the Prado Museum in Madrid received a letter requesting that the museum should relinquish four of its star attractions from its collection. The paintings in question are: Hieronymus Bosch’s The Garden of Earthly Delights (1500-05) and Table of the Mortal Sins (c. 1480); Tintoretto’s The Foot Washing (1548-49); and Rogier van der Weyden’s Descent from the Cross (c. 1435).

The letter was written by Spain’s National Heritage office in the hope that the paintings will be transferred to a new museum that is being built to house the Royal Collection. The museum is due to open in 2016 and will cost around  €160m.

The works have been in the care of the Prado since the 1930s when they were removed from the Royal Monastery of San Lorenzo de El Escorial in Madrid for their safekeeping during the civil war.

The request has sparked a dispute because the National Heritage office says that the works have been in “temporary storage” and that “a National Heritage law of 1982 reinforced this [position]”. The Prado, however, says that the “transferral was decreed by the head of state in 1943,” and that “these masterpieces are public, not private, property, and belong to all Spaniards. They are an essential part of the Prado’s identity.”

The chairman of the Prado’s board, José Pedro Pérez-Llorca, put it more strongly. In a public declaration last week, he said: “If he is waiting to have the paintings in his place, he has to wait until hell freezes over.”

We’ll keep you updated on any developments, and you can read more in the New York Times.