A lifelong admirer and follower of Menachem Begin, Harry Hurwitz devoted a major part of his career to working in the diaspora, believing he made a greater contribution to right-wing Zionism outside Israel.

Then, in 1977, Begin telephoned saying that Israel needed him. He moved to Jerusalem and three days later started a career in Israeli politics at the top - as Prime Minister Begin's advisor.

Before settling with his family in Johannesburg in 1934, 10-year-old Harry Zvi Hurwitz was already an enthusiastic right-wing or "revisionist" Zionist, having heard its ideological mentor, Ze'ev Jabotinsky, speak in his native Latvia.

During his high school years, he headed the revisionist youth movement, Betar, in Johannesburg and nearby towns, transforming it from a bit player to a major force in the Jewish community.

On leaving school, he started as a journalist on the movement's weekly journal, the Jewish Herald, subsequently becoming editor.

He became renowned for his translations of speeches by Begin and other leaders, allowing English-speaking readers to follow political trends in Israel. He also assumed leadership roles in the main Zionist Revisionist Organisation.

While visiting Palestine in 1946, he secretly met Menachem Begin, then head of the Irgun and in hiding from the British authorities, in Tel Aviv. The two struck up a warm relationship.

As well as becoming his friend and sounding board, he became Begin's biographer, releasing a book in 1971 which he later updated. Over the three decades after first meeting, Begin told him that his work in South Africa was more important than living in Israel.

However, soon after Begin became Prime Minister in 1977, he called Hurwitz to say the time had come to leave South Africa. He arrived in Israel in May 1978 and three days later began work as advisor to Begin.
As information attaché at the Israel Embassy in Washington from 1980-83, he covered the crises of Israel's bombing of Iraq's nuclear reactor in Osirak in 1981 and the invasion of Lebanon in 1982, which led to the Sabra and Shatila camp massacres. He also pioneered relations between Israel and evangelical Christians.

Returning to Jerusalem, he became advisor on world Jewry, a role he continued when Yitzhak Shamir succeeded Begin in 1983. He enjoyed the outcome of his coaching of Shamir for a House of Lords speech in 1991. The Lord Speaker complimented the premier on his English, adding: "Where does your South African accent come from?"

When Begin died in 1992, Hurwitz pledged to establish a memorial centre for his life and work. The Menachem Begin Heritage Centre opened in Jerualem in 2004. It contains a library, museum, research institute and archives.

As president of the centre, he worked full-time on research and was documenting correspondence between Begin and Egyptian President Anwar Sadat from 1977-1981 when he stopped for the onset of Rosh Hashanah. He died on the second day of the festival.

This is not the first time that Hurwitz's life has been summed up in print. In 2001 the Jerusalem Post published an obituary in the mistaken belief that he had died.

Hurwitz phoned its author, his friend Shmuel Katz, making out that he was contacting him from heaven to thank him for his favourable piece.

He is survived by his wife Freda, son Hillel, three grandchildren and two great-grandsons.