A Quincy attorney said Monday that he has alerted federal authorities that one of his clients believes he knows the name of the mystery man seen in surveillance video at the Isabella Stewart Gardner Museum the night before thieves robbed the museum of $500 million in paintings in 1990.
George G. Burke said he passed the name on to investigators on behalf of his client, who wanted to remain anonymous because “he is afraid of being killed.”
In a telephone interview, Burke said his client was once in the antiques business, as was the man he believes is in the video.
The FBI released the never-before-seen video to the public last week in hopes of sparking new leads in the unsolved heist of $500 million in paintings in 1990. The video was recorded one day before two men dressed as Boston police officers entered the museum, tied up the guards, and stole 13 works of art, including paintings by Rembrandt, Vermeer, and Manet.
“He recognized the person in the video,’’ Burke said of the client, who hired him more than a decade ago for a civil matter but reestablished contact with a call over the weekend. Burke declined to make public the name of his client or the name of the individual his client believes is in the video.
Burke said the client does not want to be connected to the crime — or the people responsible for the robbery — and won’t be speaking with federal authorities.
“He wants me to give the name to the US attorney, which is what I have done,’’ said Burke.
A spokeswoman for US Attorney Carmen M. Ortiz confirmed Monday that the office had received a fax from Burke and that prosecutors have “forwarded it to investigators.’’
A spokeswoman for the Boston office of the FBI, the lead investigative agency in the Gardner heist, said that a “handful” of tips have reached the FBI, since the video was released publicly last week.
“We will take all our leads seriously,’’ said FBI spokeswoman Kristen Setera, who declined to comment on Burke’s tip. “We will follow up on each and every one of them.’’
The video shows a former Gardner museum guard, Richard Abath, letting an unidentified man into the museum at 12:49 a.m., on St. Patrick’s Day 1990, in violation of museum protocol. Abath has recently told federal investigators that he does not recall the incident, the Globe has reported. Abath is now in his late 40s and lives in Vermont. He has long denied any connection to the robbery even though he opened the door to the thieves.
In the newly released video, the unidentified man stands by the watch desk for several minutes, remains out of view of the museum’s surveillance camera for most of the time, and appears to be fumbling through paperwork, or possibly showing something to Abath, who was then 23 years old.
During the robbery about 24 hours later, Abath and another guard were both tied up by the thieves, who also stole that night’s surveillance camera video.
Burke said his client tried to avoid doing business with the man in the video because he was associated with both art thief Myles Connor and William Youngworth, a South Shore man who once claimed he could get the paintings returned.
Burke said the man identified by his client is alive. The FBI has said it believes the two men who committed the robbery masquerading as police officers are dead.
“My hope is that this may be the break they need, but who knows?’’ said Burke.
Prosecutors have contended that another man they believe is linked to the stolen artwork, Robert Gentile, 79, of Manchester, Conn., told an undercover FBI agent that he had two of the stolen paintings and was willing to sell them.
Gentile, a reputed mobster, is currently being held in Connecticut on a federal weapons indictment and has repeatedly denied any knowledge of the whereabouts of the artwork, according to his lawyer and court filings.
In 2013 the FBI publicly disclosed for the first time that agents believe they know who took the art, and that the works had made their way through underground organized crime channels from Boston through Connecticut to Philadelphia, where they were last believed to be seen.
Anthony Amore, the Gardner’s security director, said he was aware of the new tip from Burke and that he is vetting it with federal investigators.
“I’ve been in close contact with federal authorities, not just about this one, but about all the tips” that have come in. Amore declined to comment when asked if he thought Burke’s information was legitimate.
Amore said that since the release of the new surveillance footage, the museum has received dozens of tips in the form of phone calls, e-mails, and letters.
“People are very eagerly trying to help us,” Amore said. “We’re very grateful.”John R. Ellement can be reached at email@example.com. Follow him on Twitter @JREbosglobe. Travis Andersen can be reached at firstname.lastname@example.org. Follow him on Twitter @TAGlobe.