BOSTON (CBS) – The $10 million reward being offered for the pieces stolen during the Isabella Stewart Gardner Museum heist is about to expire.

The biggest private reward ever offered will drop back to $5 million on January 1st.

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Stolen: Johannes Vermeer, The Concert, about 1665, oil on canvas (Credit: Isabella Stewart Gardner Museum, Boston)

“What we’re looking for are facts, we’re looking for people who can tell us where we can go get our paintings,” said the museum’s director of security Anthony Amore.

Thirteen pieces including works by Rembrandt, Degas, Manet and Vermeer were all swiped by two thieves dressed as cops in the early morning hours of March 18, 1990.

“It’s the biggest property theft in the history of man,” said Amore.

Stolen: Rembrandt van Rijn, Portrait of the Artist as a Young Man, about 1633, etching (Credit: Isabella Stewart Gardner Museum, Boston)

The art is worth an estimated $500 million and Amore is still optimistic 27 years after the art heist.

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“History has shown that when paintings are stolen they stay pretty close,” said Amore.

He explains it’s extremely hard to sell the masterpieces meaning they’ll most likely be tucked away under a bed, in a basement or attic waiting to be discovered.

Stolen: Édouard Manet, Chez Tortoni, about 1875, oil on canvas (Credit: Isabella Stewart Gardner Museum, Boston)

Until then, their frames remain hanging empty inside the museum.

“It’s a message to the public that we’re never going to forget these paintings there is only one place they belong and that’s here in Ms. Gardner’s collection,” said Amore.

Anyone with information can call Anthony Amore at 617-278-5114 or send him an email

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