A new public awareness campaign will be launched by Federal officials investigating the infamous 1990 art heist at Boston's Gardner Museum.

Thieves swiped a cache of 13 artworks - by the likes of Rembrandt, Vermeer, Degas, and Manet - valued at about $500 million in the world's biggest art heist.

Following the detainment last year of notorious mobster Whitey Bulger, who was long suspected of knowing about the crime, investigators have focused on ties to the late Mafia figure Robert Guarente. Two homes have been searched in the last eight months and a grand jury activated.

In the hope of discovering leads, a billboard and television advertisement campaign may be launched, similar to the one that netted Bulger in Santa Monica, Calif.

Investigators offer the possibility of immunity from criminal prosecution for any information about the paintings, and the museum has put up a $5 million reward for the recovery of the paintings in good condition.

Click here for composite sketches of the thieves from the Boston Herald.