David-Maria Jaeger is no ordinary priest. He has worked closely with two popes, spent 19 years as a legal adviser to the Vatican in its talks with Israel and, last month, was sworn in as a judge at the Papal Court, the highest court of the Catholic Church.

But what really marks out Mr Jaeger is that he is also a patriotic Israeli Jew. He says: "I am truly happy and grateful to belong to the Jewish people. In human terms it is who I am - a Jew - and specifically, an Israeli Jew. And of course, I cannot conceive it ever being otherwise; why should it ever be?"

Mr Jaeger's Jewish background fed into his previous roles at the Vatican: he was widely reported as being lead negotiator in the Vatican's Fundamental Agreement with Israel in 1993, which established diplomatic relations between the two.

His journey from a Tel Aviv suburb to, as he puts it, "administering justice in the name of the Pope" is less well known, however.

After leaving the Zeitlin religious high school in Tel Aviv, a teenaged Jaeger experienced a crisis of faith. As reported by Ha'artez, he disappeared for six years and, when he returned, aged 22, he told a friend: "You know, I'm now in the church."

As he explains: "I lost religious faith completely, so that I converted to Christianity, not from Judaism, but from unbelief. And this was fundamental to the way I approached the Christian faith, considered it, studied it and embraced it - that I was coming at it from unbelief."

He says that he never came under any criticism from anyone - family or friends - over his change of faith.

Born in Tel Aviv in 1955, Mr Jaeger's father, Gershon, was headmaster of the Kugel High School in Holon. His mother, Dvora, was Brazil's deputy consul
in Israel.

Israel in the 1950s and 1960s was, for him, was an egalitarian society. "In my class, we were the sons of government officials, professionals, businessmen and scientists, as well as the sons of street sweepers and labourers."

He still has great affection for Tel Aviv, and, perhaps surprisingly for a Vatican official, praises its modernity: "It is an open city, a city that has always spoken of the newness of Israel, the new beginning that our people so much wanted. Israel is for me first of all Tel Aviv."

On Pius XII, the wartime pope who has been accused of indifference to the Holocaust, Mr Jaeger says there is "abundant evidence" of his "efforts to save Jewish lives".