Jerusalem, July 5, 2018 (AFP)

A former Israeli government minister went on trial on Thursday on charges of spying for arch-foe Iran in a case which has been kept under tight wraps on security grounds.

Gonen Segev, who served as energy and infrastructure minister from 1995 to 1996, is charged with "espionage against the state of Israel, assisting the enemy in time of war and passing information with the intention of harming state security."

Journalists were excluded from the hearing, which was held behind closed doors, an AFP correspondent reported. Most of the detailed charge sheet has been redacted in its published version.

Segev's defence lawyers have complained that most details of the charges were under a state-imposed blackout and the little which had been released gave a misleading impression.

Segev is accused of providing Iran with "information related to the energy market, security sites in Israel, buildings and officials in political and security bodies, and more" while he was living in Nigeria between 2012 and his arrest at Israel's Ben Gurion airport in May this year.

He is accused of travelling to Iran to meet his minders.

Segev, who served in the Labour government of prime minister Yitzhak Rabin after defecting from the far right to cast the decisive vote in favour of the Oslo II agreement with the Palestinians, has previously served prison time on criminal charges.

In 2004 he was charged with trying to smuggle 30,000 ecstasy pills into Israel from the Netherlands, using a diplomatic passport with a falsified expiry date.

The following year he admitted the charges as part of a plea bargain agreement.

He has also been convicted of attempted credit card fraud.