The sentence comes as Segev pleaded guilty to charges of serious espionage and passing information to an enemy.
The disgraced former doctor was recruited in 2012 by Iran’s embassy in Nigeria, the Israel Security Agency (ISA) said at the time of Segev’s arrest last summer.
He had relocated to Africa’s most populous nation after serving time in an Israeli prison for a 2006 drug smuggling conviction. Segev had been found guilty of attempting to bring 25,000 Ecstasy pills into Israel from the Netherlands.
According to the ISA, Segev met twice with Iranian operatives, knowing they were from Iranian intelligence. A gag order remains in place on other details of the investigation and the plea agreement.
Segev served in the Israeli parliament, the Knesset, from 1992 to 1996 in the Tzomet and Yi-ud political parties. He served as Minister of Energy and Infrastructure under prime ministers Yitzhak Rabin and Shimon Peres between 1995 and 1996.