The FBI agent in charge of the investigation into the theft of $500 million worth of masterpieces from a Boston museum nearly a quarter century ago says the bureau has confirmed sightings of the missing artwork from credible sources.

MyFoxBoston.com first reported that FBI Special Agent Geoff Kelly, who lead the international investigation for more than 10 years, says the trail for the missing artwork has not grown cold.

"We believe that over certain periods of time, this artwork has been spotted," Kelly told the station. "There have been sightings of it, confirmed sightings."