Thirty-six years ago, the teenage daughter of a Vatican City employee vanished off a Rome street on her way home, beginning one of Italy's most enduring mysteries: Over the years, reports have variously linked her fate to the Sicilian Mafia, the KGB and the plot to assassinate Pope John Paul II.

On Thursday (Friday NZ time), the latest trail led her family and a Vatican-appointed forensic scientist to two tombs inside the Vatican walls, the burial places of princesses well over a century dead.

The team only found another mystery: The tombs were empty. Even the bodies of the dead