Seven people on trial for stealing works by Monet, Sisley and Brueghel from a French museum say that the crime was instigated by Robert K. Wittman, the FBI's well-known art detective.

The 2007 heist from Nice's Musée des Beaux Arts yielded the gun-toting thieves four paintings -- Breughels' Allegory of Water and Allegory of Earth along with Alfred Sisley's Avenue of Poplars at Moret and Claude Monet's Cliffs Near Dieppe. Estimated at 22 million euros, the works would fetch only a fraction of that amount on the black market.

Facing 30 years in prison for armed robbery, the men said they acted on a comment from Wittman who was trying to flush out the perpetrators of the unsolved 1990 Gardner Museum heist. Missing from the Boston museum are works by Vermeer, Rembrandt, and Degas, worth about $500 million.

Wittman was working undercover when he met with a Miami-based contact, "Sunny" Ternus, who claimed he knew of the whereabouts of the stolen Gardner paintings.

The suspects' lawyer said that his clients were amateurs who were motivated to do the crime in order to fulfill Wittman's supposed wish for "Dutch paintings" as told to Ternus during a Miami yacht party staged by the FBI.

"These canvasses disappeared in order to recover two key paintings belonging to US heritage. I'm not sure that the US would appreciate it if French agents acted likewise," said the gang's lawyer. He accuses Wittman of "police provocation" and wants the charges dropped.