The mysterious disappearance of Emanuela Orlandi has captivated Italy for 40 years. Emanuela was 15 years old when she disappeared on June 22, 1983, while she was returning from a flute lesson in Rome.

Now the case of her disappearance under mysterious circumstances entered a new chapter on Tuesday when her brother met with a Vatican investigator whom Pope Francis has given free rein to get to the bottom of the case.

Emanuela Orlandi was the daughter of a Vatican usher whose family lived in the Vatican. To find out exactly what happened to her, several investigations were conducted, including the reopening of tombs and grave sites.

Following the release of the Netflix series "Vatican Girl" in late 2017, the case has garnered new interest on a global scale. After receiving data from his retired predecessor, Vatican chief prosecutor Alessandro Diddi restarted an earlier, unsuccessful Vatican probe in January.

Laura Sgro, lawyer for the Orlandi family, talks to the press.

In an interview, Mr. Diddi claimed that Pope Francis has a strong desire for "the truth to emerge without any reservations" in this situation.

Pietro, the elder brother of Emanuela, and Laura Sgro, the family's attorney, spent more than five hours on Tuesday afternoon meeting with Mr. Diddi in the Vatican.

"We hope this can shed light on this episode and write a page of history," Sgro told reporters afterwards, saying that the Vatican's openness and the pope's determination were "absolutely positive."

Theories about Orlandi's disappearance have run the gamut. In the 1980s, Italian media speculated she had been kidnapped in an attempt to secure freedom for Mehmet Ali Agca, the Turk jailed in 1981 for trying to assassinate Pope John Paul II, though nothing came of the link and the suggestion faded.

Other reports linked her to the grave of Enrico De Pedis, a mobster buried in a Rome basilica. His tomb was opened in 2012, but nothing was revealed, and in the interview with Corriere della Sera, Diddi said the suspected link between the girl's disappearance and the Rome crime clan had been "over evaluated".

In 2019, the Orlandi family received an anonymous letter saying Emanuela's body might be hidden among the dead in the Teutonic Cemetery just inside the Vatican walls, where a statue of an angel holding a book reads "Requiescat in Pace," Latin for "Rest in Peace."

Two tombs were opened, but nothing was found-not even the bones of the two 19th-century princesses supposed to be buried there. They apparently had been moved during restructuring work decades before Orlandi was born.

In 2018, bones found during ground work at the Vatican embassy in Rome sparked a media frenzy, suggesting they might belong to Orlandi or to Mirella Gregori, another teenager who disappeared the same year. DNA tests were negative.

Last month, Italy's lower house approved the establishment of a parliamentary commission to investigate the disappearances of both girls.

Police have never excluded the possibility that Orlandi may have been abducted and possibly killed for reasons with no connection to the Vatican, or been a victim of human trafficking.