Raphael painting found in store room

A painting left to collect dust in a store room for more than 30 years is in fact a priceless work by Raphael, Italian art experts have said.

The small portrait of a woman had lain discarded since the 1970s at the Ducal Palace in Sassuolo near Modena, after experts declared it to be an unremarkable 17th-century copy of a lost painting from the Raphael School.

But a chance viewing of the work by Mario Scalini, interim arts superintendent for Modena and Reggio Emilia, led to a rethink. His suspicions were aroused by the painting's extravagant golden frame as well as its elegance. "What really got me on the right track was a close look at the frame, a superb 17th-century gallery frame." he said. "It would have been highly unusual to bestow such a prestigious frame on a work that was considered of little worth."

He recruited other authorities, including the leading restoration expert, Lisa Venerosi Pesciolini, to examine the portrait. With the use of infrared and ultraviolet analysis at the Art-Test laboratories in Florence, she was able to see how the painting's original form had been altered over the years.

The experts believe that the portrait, measuring just 30cm by 40cm, is the first version of the famous Madonna of the Pearl – detail above – in Madrid's Prado Gallery. They plan to put the so-called "Modenese pearl" on show in Siena.