A court in Jerusalem has sentenced an Israeli man to four-and-a-half years in prison for offering to spy for Iran, according to court documents.

Tuesday's court ruling said 46-year-old Yitzhak Bergel admitted to charges of contacting a foreign agent, intent to commit treason and attempting to aid an enemy of Israel.

Bergel belongs to the fringe ultra-Orthodox Jewish sect Neturei Karta, which opposes Israel's existence on religious grounds.

It opposes a Jewish state in the Holy Land until the coming of the messiah. Adherents of the sect have met with Iranian leaders in Iran in recent years.

The verdict says Bergel flew to Berlin in 2011, contacted the Iranian embassy there and offered to collect intelligence about Israel. No damage was caused to state security, according to Israel.

Shin Bet, Israel's domestic security agency, said that Bergel had admitted during an interrogation that his deeds were "out of spite for Israel and for financial gain".

Neturei Karta is a very small splinter group from within ultra-Orthodox Jewry with members in Israel and abroad.

Israel, the region's sole if undeclared nuclear power, accuses Iran of being bent on its destruction, and fears the Islamic republic intends to develop nuclear arms for that end. Tehran rejects the accusation.