MILAN (AP) — The director of the Uffizi Gallery in Florence is urging Germany to return a Dutch masterpiece stolen by Nazi troops during World War II.

Eike Schmidt said in a New Year's appeal on Tuesday that the still-life "Vase of Flowers" by Dutch artist Jan van Huysum is in the hands of a German family who hasn't returned it despite numerous appeals. Instead, intermediaries for the family have demanded payment for its return to Italy.

Schmidt said "the painting is already the inalienable property of the Italian State, and thus cannot be 'bought.'"

The oil on canvas had been hanging as part of the Pitti Palace collection in Florence from 1824 until the outbreak of World War II. It was moved for safety during the war, then stolen by retreating German troops.