MILAN (AP) — A Botticelli portrait of a humanist poet that long hung in Madrid's El Prado Museum is being offered this week for sale during London's Frieze Masters art fair for $30 million. But a Spanish law on cultural treasures might create difficulties for a foreign buyer seeking to bring the treasure home.

The painting dating from 1500 is billed as the last by the Florentine Renaissance master Sandro Botticelli in private hands outside of Italy and on the international art market.

The sale is being arranged by Trinity Art Gallery in London. Gallery owner and Italian art dealer Carlo Orsi said the painting's strength is in its expression and the significance of the person it portrays: Michele Marrulo, a well-known Latin poet of the Medici court and adventurer of the Renaissance.