NEW HAVEN, Conn. -- It remains the largest art heist in history, a brazen robbery in which two thieves disguised as police officers walked into Boston's Isabella Stewart Gardner Museum, disabled two guards and stole masterworks worth more than half a billion dollars.
The 1990 robbery and the recovery of the paintings have puzzled investigators for more than two decades.
Now federal authorities appear to be pinning some hope of solving the mystery on a 75-year-old reputed mobster from Connecticut, Robert Gentile, who is jailed in a drug case.
The FBI believes Robert Gentile "had some involvement in connection with stolen property" related to the art heist, Assistant U.S. Attorney John Durham said in federal court in Hartford this week. Durham said FBI agents have had unproductive discussions with Gentile about the theft, but didn't elaborate on his allegations.
Gentile's attorney, A. Ryan McGuigan, called the notion preposterous. He said Gentile has lived with his wife in the same small house in a Hartford suburb for 50 years and has no idea what prosecutors are talking about.
"He doesn't know anything about art, he's never been to an art gallery in his life, couldn't tell a Rembrandt from an Elvis painting," McGuigan said in an interview.
Durham spoke at a hearing over whether bail should be set for Gentile in the drug case. A judge ordered Gentile to remain held without bail, saying he's too dangerous.
Prosecutors declined to comment further.
Authorities first approached Gentile about the art heist about two years ago, McGuigan said.
"They're not interviewing him about him actually participating in the heist," McGuigan said. "They may or may have not interviewed him about any knowledge that he may have about the whereabouts of the paintings."
When Gentile offered no information, authorities dispatched an undercover witness to buy prescription drugs from him, McGuigan said.
"They set you up and entrap you and throw you in a federal prison at 75 years old until you'll be tortured enough to talk to them about information that you don't have," McGuigan said.
If Gentile were some type of arch-criminal, he would have figured a way to get the $5 million reward offered in the case, McGuigan said.
Gentile, of Manchester, Conn., and associate Anthony Parente, also 75, were charged last month with selling prescription painkillers that were obtained illegally. Federal agents say they found several guns, ammunition, homemade silencers, a blackjack, three sets of handcuffs, a bulletproof vest, a Taser, ammunition, police scanners and brass knuckles at Gentile's home as well as $22,000 at the bottom of a grandfather clock.
Gentile has not been charged in the art heist.
Prosecutors say Gentile is a member of a Philadelphia crime family. His lawyer denies the mob allegation.
The defense says Gentile, who owned an auto repair business, has a larceny conviction but no history of violent crime. His attorney said he is a devoted family man who left school in the ninth grade and now his health is in serious decline, with back and heart troubles and he can barely walk.
The Gardner museum recently marked the 22nd anniversary of the heist in which thieves struck as Boston finished celebrating St. Patrick's Day. They bound and gagged two guards using handcuffs and duct tape in the early hours of March 18. In a little over an hour, they removed masterworks including those by Rembrandt, Vermeer, Degas and Manet, cutting some of the largest pieces from their frames.
The museum continues to offer a $5 million, no-questions-asked reward. Federal prosecutors, who made a renewed push to recover the paintings in 2010, are offering immunity.
Special Agent Geoff Kelly, the FBI's lead investigator on the Gardner Museum heist, would not comment on Gentile, saying the FBI would refer all questions to the U.S. Attorney's Office in Connecticut.
"The FBI has been aggressively investigating the Gardner heist for 22 years," Kelly said. "The investigation is active and ongoing. The Boston office is currently working with our New Haven office and other offices to pursue all viable leads."
Investigators continue to get strong leads, Kelly said.
"Our tenacity in continuing to pursue this investigation is motivated by the cultural significance of the stolen pieces, and our investigation will not stop until the pieces are recovered."
Authorities have pursued numerous leads over the years that have taken them as far as France and Japan, said Ulrich Boser, author of "The Gardner Heist."
"It's really quite remarkable no one has come forward," Boser said, noting the $5 million reward. "This is just this incredible whodunit."
Associated Press writer Denise Lavoie in Boston contributed to this report.