Wartime Pope Pius XII expressed unease when Vatican efforts to intercede with the Nazi German occupiers on behalf of Italian Jews facing deportation were reported in the press in October 1943, out of the fear that public exposure would hamper similar initiatives to save Jews.

The revelation was highlighted by several Italian media outlets on Monday, as the Vatican opened the secret archives of Pius XII — the Italian cardinal Eugenio Pacelli who became pope in 1939, on the eve of World War II and the Nazi Holocaust.

The degree to which Pius assisted and advocated for Jews facing the Nazi genocide has been furiously debated among historians for decades. Some accounts of the period have portrayed Pius as a confirmed antisemite who colluded with Hitler’s regime, while others have asserted that thousands of Jews were saved from death by the discreet diplomacy practiced by the pontiff.

The item in the archive from October 1943 related to the deportation of nearly 1,300 Jews from the ghetto in Rome. A dispatch from the Vatican’s press and information service reported that “on the night of 15-16 October a considerable number of Jews were arrested in various parts of Rome (stop) after being held 24 hours in the military college were transported to an unknown destination (stop) it is said here that the Holy See was concerned that similar events should not be repeated and in favor of particular cases.”

Alongside this dispatch was a comment in Pope Pius’s own handwriting expressing concern that the Vatican’s stance was being reported.

“Is it prudent for the press service to send this news?” he wrote.

Pius then added that he was “well aware that it would not help to wake sleeping dogs, especially not Nazis, to humanitarian actions originating from the Apostolic Palace.”

The Vatican normally waits 70 years before it publishes archive documents, but an announcement from Pope Francis last year confirmed that the Pius XII archive would open its doors in March 2020.

“The church is not afraid of history,” Francis said at the time.

Jewish groups warmly welcomed the archive’s opening on Monday.

“We trust that the independent scholarly review of these archival materials will provide greater clarity as to what positions and steps were taken during this period by the Holy See, and help resolve the persistent debates and controversy in this regard,” said Rabbi David Rosen — International Director of Interreligious Affairs for the American Jewish Committee (AJC) — said in a statement.

“Such necessary transparency is also to the credit of the Church and will further enhance the mutual trust and excellent relations between the Catholic Church and the Jewish community built up over the last 55 years,” Rosen said.

In a separate statement, Menachem Rosensaft — associate executive vice president and general counsel of the World Jewish Congress (WJC) — expressed “our enormous gratitude and appreciation to Pope Francis for taking this step.”