Yitzhak Ben-Zvi, the second president of Israel, is claimed by Avraham Silberg, one of the assassins of Jacob de Haan, to have approved of de Haan's murder.
Born in Poltava, Ukraine, Ben-Zvi was the eldest son of Zvi Shimshelevitz, who later took the name Shimshi. He was active in the Jewish self-defense units organized in Ukraine to defend Jews during the pogroms of 1905, and joined the Poalei Zion (Workers of Zion) Zionist political party. He emigrated to Palestine in 1907, and settled in Jaffa, where he helped organize the HaShomer self-defense unit in the country. In 1909, he organized the Gymnasia High School in Jerusalem together with Rahel Yannait whom he later married in 1918
See this Wikipedia (English) articleEvents involving Yitzhak Ben-Zvi: