JERUSALEM (JTA) — The former head of Israel’s Mossad intelligence agency will lead a program to help immigrants from the Soviet Union prove their Jewishness.

Efraim Halevy on Sunday was tapped to become chairman of the Shorashim program, part of the Tzohar Rabbinical organization, which helps to involve non-religious couples and their families in religious wedding ceremonies and other life-cycle events.

The program operates out of offices in Moscow and Kiev, as well as in Israel.

“For years we were imploring these Jews to come home to Israel and now we’re going to reject them because they can’t easily prove their Jewish ancestry?” Halevy said at the program’s annual meeting. “There is an answer and that is what this program offers.  But if we don’t commit ourselves to it then we’ll go down as the biggest traitors in Jewish history.”

The Shorashim project was founded in 2005 by the Tzohar organization to help immigrants from the former Soviet Union to clarify their Jewish status when dealing with the rabbinate. These certifications are mandatory under Israeli law for any couple of questionable ancestry who are looking to marry under official Israeli law. The certification often involves sending emissaries into archives and cemeteries in tiny Russian and Ukrainian villages to obtain the levels of proof necessary to determine that an immigrant to Israel is of certain Jewish ancestry.

Shorashim is funded by the Harry Triguboff Foundation based in Sydney, Australia, the Friedberg Charitable Foundation of Toronto, Canada and the government of Israel.