Underwater thieves have evaded an array of laser systems that measure millimetric shifts in the Costa Concordia shipwreck and 24-hour surveillance by the Italian coast guard and police to haul off a symbolic booty - the ship's bell.
The giant cruise liner capsized off the Tuscan island of Giglio after hitting a rock on January 13, killing at least 25 people. Seven people are still unaccounted for.
Prosecutors have accused Captain Francesco Schettino of causing the accident by bringing the multi-storey Costa Concordia, which was carrying more than 4,200 passengers and crew, too close to the shore.
Now prosecutors have opened an investigation to find out who filched the modern-day Titanic's bell.
Judicial sources said on Thursday thieves nabbed the ship's bell more than two weeks ago from one of the decks of the Costa Concordia, which is submerged in 8 meters (26 feet) of water.
Investigators suspect more than one person was involved in stealing the heavy bell, etched with the ship's name and 2006, the year it was christened.
Ships bells were traditionally used to signal half-hour intervals in a four-hour watch.