On the eve of World War II, a woman closed up her Parisian flat, headed south and never returned. Seventy years later, after she had passed away at age 91, experts tasked with compiling an inventory of the woman's estate discovered her treasure trove in Paris.

The Telegraph reports that one expert said it was like stumbling into the castle of Sleeping Beauty, where time had stood still since 1900.

Among the surprises was a vibrant portrait of a mysterious lady by famed Italian artist Giovanni Boldini (1842-1931).

Marc Ottavi, a specialist in 19th and 20th century paintings and sculptures, was enlisted to authenticate the painting.

Exciting details emerged: the flat yielded up a love note from the artist Boldini to the actress Marthe de Florian. The woman who had abandoned life in Paris decades ago, but paid the flat's rent, was in fact de Florian's granddaughter. Ottavi then found an inventory listing of the painting noted by Boldini's wife.

The rediscovered portrait of the pink-clad de Florian, whom Boldini painted in 1898, went to auction where the work fetched €2.1 million (approx. US$2.9 million), a world record for the artist.