Steven Sotloff, the Jewish-American journalist beheaded by Islamic State terrorists in Syria, fasted on Yom Kippur last year without his captors discovering he was Jewish, according to a former fellow captive.

Sotloff, reported on Wednesday to be a dual Israeli-US citizen, was remembered in Israel throughout the day by people who had worked with the young journalist during his time here and while reporting around the Middle East.

Friends and colleagues recalled Sotloff as an adventurous man who was fascinated with the Middle East. His death and connection to Israel, kept under wraps while he was held hostage, made top news in the country.

Speaking to Yedioth Ahronoth, an ex-prisoner who said he was held along with Sotloff, said the reporter tried to keep to some Jewish traditions, even while keeping his heritage secret from his Islamist captors.

On Yom Kippur, the unnamed ex-hostage said, he managed to fast.

“He said to them that he is sick and doesn’t want to eat, despite the fact that they served us eggs that day,” he said.

The source also said that Sotloff would covertly pray toward Jerusalem by observing which way the Muslims were facing during prayer, and changing the direction slightly.

An Israeli official said Wednesday that Sotloff was an Israeli citizen. Foreign Ministry spokesman Paul Hirschson wrote on his personal Twitter feed: “Cleared for publication: Steven Satloff was Israel citizen RIP,” misspelling the journalist’s last name.

The ministry refused to confirm Sotloff’s citizenship to the Times of Israel. But a former professor of his at the Interdisciplinary Center Herzliya told Ynet that Sotloff had indeed gained Israeli citizenship.

Israel’s military censor office cleared the information for publication, suggesting Israel had tried to conceal the news to protect Sotloff, 31.

Sotloff’s citizenship did not appear to have influenced his fate.

Sotloff, a grandson of Holocaust survivors who grew up in Miami, studied foreign relations at the IDC. He then began reporting from countries throughout the Middle East, returning to Israel for the 2013 Maccabiah Games.

On Wednesday, IDC President Prof. Uriel Reichman said “Steven’s murder proves to us that the immunity of journalists, once granted even in times of warfare in order to protect the truth and defend free speech, has been erased.”

Journalist Steve Sotloff in Jordan, 2009. (photo credit: Facebook/Oren Kessler)

Journalist Steve Sotloff in Jordan, 2009. (photo credit: Facebook/Oren Kessler)

London-based analyst Oren Kessler, who corresponded with Sotloff, said he never shared his Jewish identity with anyone in the field, opting instead to tell locals that he had been raised Muslim but secular, without mosque affiliation. He sometimes even chose to tell people that he was of Chechen origin, and that Sotloff – a name that rings decidedly Jewish to those familiar with Jewish names – was actually a Chechen name.

In Yemen, Kessler said, Sotloff once allowed locals to give him a “quickie conversion,” a 10-minute ceremony meant to return him to his purported Islamic roots.

Sotloff vanished a year ago in Syria and was not seen again until he appeared in a video released last month showing the beheading of US journalist James Foley.

While he was missing, Internet sites were scrubbed with any mention of Sotloff’s Jewish or Israeli identity, as his family and journalists attempted to shield him from harm.

Dressed in an orange jumpsuit against an arid Syrian landscape, Sotloff was threatened in the Foley video with death unless the US stopped airstrikes on the Islamic State.

In the video distributed Tuesday and titled “A Second Message to America,” Sotloff appears in a similar jumpsuit before he is apparently beheaded by a fighter with the Islamic State, the extremist group that has conquered wide swaths of territory across Syria and Iraq and declared itself a caliphate.

The White House said Wednesday it had confirmed the video was authentic.

Sotloff’s family could not be reached for comment.

Debra Kamin, AP and JTA contributed to this report.