HARTFORD, Conn. — A reputed mobster suspected of having knowledge about long-sought stolen artwork is due to appear in court in an attempt to get a weapons case dismissed.

Robert Gentile has a hearing Wednesday in federal court in Hartford, Connecticut.

The FBI believes the convict with a criminal record dating to the 1950s knows something about the 1990 theft of $500 million in art from Boston’s Isabella Stewart Gardner Museum.

Gentile’s attorney, A. Ryan McGuigan, has argued that his client’s most recent arrest, last April, was orchestrated by federal investigators to press him for information about the missing artwork. McGuigan says his client is not withholding any information.

The 13 pieces of art stolen from the Boston museum have never been found and nobody has been charged in the robbery.