Jewish underground leader; Born July 15, 1917; Died May 20, 2009.

Yehoshua Zettler, who has died aged 91 following a stroke, was one of the founding members of the Stern Gang, the a violent pre-state Jewish movement, and mastermind of the assassination of a top UN envoy in 1948.

Zettler was one of the original members of the militant Irgun group and its more extreme Stern Gang breakaway LEHI (a Hebrew acronym for Israel Freedom Fighters), serving under two future Israeli Prime Ministers: Menachem Begin and Yitzhak Shamir.

He spent seven years in prison for his role in a bank robbery. Later, as the LEHI Jerusalem commander, he participated in several battles during Israel's war of independence in 1948-49. However, he was most renowned for planning the assassination of UN mediator Count Folke Bernadotte in Jerusalem in September 1948. Bernadotte was a member of the Swedish royal family and, as the UN envoy, he was responsible for mediating between Jews and Arabs to try to stop the war that followed Israel's creation. He angered LEHI members by suggesting that the boundaries of a 1947 UN partition plan be revised to put Jerusalem under UN control and hand Israel's Negev desert to Jordan.

Previously, as head of the Swedish Red Cross during the Second world War, Bernadotte negotiated with Nazi Heinrich Himmler to save thousands of Jews from concentration camps. LEHI commanders considered Bernadotte to be a British agent who co-operated with the Nazis. They picked Zettler to have him killed. A LEHI team blocked his limousine, and a gunman killed Bernadotte and a French officer.

Following the war, Zettler settled in Tel Aviv, where he owned a filling station. "This country owes him a great debt that Jerusalem is today in our hands," said nationalist lawmaker Arieh Eldad, whose father, Yisrael, was one of LEHI's leaders. "It was not clear at the time if the country would survive, and Bernadotte was suggesting to hand Jerusalem over to the Arabs."

Zettler is survived by his widow and a daughter. By ARON HELLER