Jewish businessman and philanthropist Ronald Lauder bought the gold-encrusted 1907 Portrait of Adele Bloch-Bauer I in June 2006. The Klimt masterpiece, which had been looted from its Jewish owner by the Nazis 70 years before, made history when it fetched £73 million, the largest sum ever paid for a painting.

Bought at auction by the head of the cosmetics giant Estee Lauder for his New York art gallery, the picture depicts the wife of Viennese industrialist Ferdinand Bloch-Bauer. During the four years it took for the portrait to be completed, the artist and Mrs Bloch-Bauer became close friends; some suggested that they became lovers. When she died of meningitis in 1925, she left a will asking her husband to bequeath the painting to the Austrian Gallery in Vienna.

Ronald Lauder pictured with his £73 million Portrait of Adele Bloch-Bauer 1

After the annexation of Austria in 1938, the painting was seized by the Nazis. The family fled to Switzerland, and when Mr Bloch-Bauer died in 1945, he left his entire estate to his brother’s children. Until legislation was passed in 1998 approving the return of all Nazi looted art, the portrait had hung in Vienna’s Belvedere Palace .

Bloch-Bauer’s niece, Maria Altmann, then 90 and living in the USA, petitioned for the return of the portrait. In 2004, the US Supreme Court upheld her right to sue the Austrian government. On its return, she put it up for sale and Ronald Lauder bought it for his Neue Galerie in New York. Lauder, whose parents founded the cosmetics firm, has long been active in recovering Nazi-looted art. “This is our Mona Lisa. It is a once-in-a-lifetime acquisition,” he told the New York Times.