The Orlandi family's lawyer Laura Sgro confirmed the probe.
She said "the secretariat of state has authorised the opening of an investigation into a grave in the Teutonic Cemetery inside the Vatican", after an anonymous tip-off indicated that people should look where a statue of an angel in the cemetery is pointing.
The Vatican said on March 27 it was handling a request from the Orlandi family to reopen a grave indicated by the angel.
Interim Vatican spokesman Alessandro Gisotti said that "at the moment I don't have any statement to make on the issue".
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