Tzefoni was born on 19.5.1923 in Turkey as Mordechai Sobol, to Yitzhak and Ahuva. The family made aliyah in 1934 and settled in Haifa. He joined the IZL in 1938, and he took part in retributive attacks against Arab rioters during the 1936-1939 riots.

After the split, he followed Yair. Because he was a wanted man, he went underground and moved to Tel Aviv, then Jerusalem, then elsewhere. At first, he was an intelligence coordinator, then the head of training division and member of the general staff for operations, which was headed by Yaakov Banai (Mazal). The Central Committee supervisor was Yitzhak Shamir (Michael). He took part in many operations, including assassinations and attacks against British targets.

Inter alia, he was in command of the attack on the officers’ barracks of the Sudanese soldiers stationed in Holon, which yielded a great deal of arms and ammunition. He also attacked the Kfar Syrkin Airfield, where a number of Spitfires were destroyed. He was involved in acquiring and forging identification cards, an essential need of the underground. He was involved in communications between Lehi and De Gaulle’s Free French forces. These began with a meeting in the home of a Haifa businessman, with a senior French intelligence officer; but they ended when the French left the region.

On 1.2.1047, he flew to Cairo, where he stayed for a few months on underground business. He then continued to France, where he took over the operations against targets in London, replacing Yaakov Eliav, who had been arrested in Belgium. He wanted to bomb the War and Colonial Offices from the air, but the Jewish pilot they had recruited fell ill. Friends of Lehi in America recommended a Canadian pilot as a substitute, but this second pilot instead turned them in to British Intelligence.

Tzefoni was arrested and imprisoned in Paris’s Maison d’arrêt de la Santé, in solitary confinement in the political wing. By his orders, the bombs were sunk in the Seine. Once he was released, he went to Belgium, supervising operations there for six months.

The Central Committee then sent him to the United States, where he took over for Binyamin Gaffner. As he met the branch directors, he encountered Beracha “Ofra” Birnbaum, who headed the Chicago branch, after spending two years in Bethlehem Women’s Prison. Tzefoni married her.

When they returned to Israel, Tzefoni worked as a contractor, breaking rocks to build the road to Sodom. Afterwards, he worked as a journalist and as the foreign news desk editor for Yedioth Ahronoth, a position he held for 32 years. They had three sons: Ofer, Gur and Danny.