Finance Minister Avraham Hirschson was questioned Thursday by a joint team of police and tax investigators, concerning allegations of fraud and the disappearance of funds from a nonprofit organization he chaired – Nili, which belongs to the National Workers' Histadrut labor federation. Thursday's questioning session in the office of the Unit for Fighting Financial Crime in Lod came as a surprise, as the minister was only supposed to undergo questioning again next week. Following today's session, and possibly another one next week, the material against Hirschson will be handed over to Attorney General Menachem Mazuz, who will decide if Hirschson needs to resign from his post as minister. Until that happens, Hirschson has no intention of resigning, according to his aides. Several reports by Channel 1 and Haaretz quote unnamed figures close to the Prime Minister hoping Hirschson will step down of his own accord and urging Olmert to dismiss him if he fails to. The police reportedly have new evidence against the minister, which appears to show that he did not fully disclose his earnings to tax authorities. The joint investigative team includes Doron Arbeli, Head of Investigations Department in the Tax Authority. Thursday's session, in the office of the Unit for Fighting Financial Crime in Lod, came as a surprise One reason for the cooperation between tax investigators and police officers is that by law, a person's tax files can only be read by Tax Authority employees. The police can only receive information from a tax file if they are granted special permission, and the only person who can grant such permission is… the Minister of Finance. Hirschson is reportedly suspected of receiving large sums of money in cash from other organizations and using them for covering gambling debts accumulated by another member of Nili, as well as for a political campaign of his own. Investigators are also probing improprieties in other organizations Hirschson was involved with, including the March of Life (which flies Israelis to Poland's death camps every year), the Volcker Fund for needy students and the pension fund Yovlim. All of the suspected transgressions involve sums in millions of shekels. Ezra HaLevi contributed to this report