The disappearance 40 years ago of Emanuela Orlandi has haunted her family, fueled conspiracy theories and provided grist for a recent Netflix series.

Matteo Bruni, director of the Vatican press office, said Jan. 9 that Alessandro Diddi, Vatican City's chief prosecutor, was opening a new file on the case, although he provided no details about the direction the investigation was expected to take.

The Italian news agency ANSA said Diddi's decision was in response to requests by Pietro Orlandi, Emanuela's brother.

Vatican investigators will begin by "analyzing the acts and documents related to prior investigations," of which there have been many, ANSA said.

Pietro Orlandi told the television RaiNews24 that he had received copies of WhatsApp messages exchanged in 2014 by "two persons very close to Pope Francis that talk about documents" related to the case that never have been published. He said he was certain someone in the Vatican knew more about what happened to his sister.

Pietro and Emanuela are the children of a Vatican employee and grew up in an apartment inside the Vatican. Emanuela disappeared in Rome June 22, 1983, when she was 15.

Over the past 40 years, dozens of theories have been advanced to explain what happened to her. Some were related to the attempted assassination of St. John Paul II in 1981 -- the idea being she was kidnapped to force the release from prison of the pope's would-be assassin -- to Vatican bank scandals and to organized crime.

In March 2019, the family's lawyer said the family had been sent a letter with a photo of an angel above a tomb in the Vatican's Teutonic Cemetery, which is reserved mainly for German-speaking priests and members of religious orders.

The letter said, "Look where the angel is pointing," according to Laura Sgrò, the lawyer.

She filed a formal petition with the Vatican to investigate the matter and, following her request, the Vatican City State court ordered the opening of two tombs near the angel sculpture.

No human remains were found in either tomb during the search in 2019, so the investigators moved to two nearby ossuaries, which are vaults containing the bones of multiple people. The forensic anthropologist who led the study of the bones said none of them were more recent than the 1800s.

The four-part Netflix series looked at the various theories floated over the past 40 years and added the idea that the disappearance had to do with a high-ranking Vatican cleric, who allegedly had made sexual advances toward the 15-year-old.