Israel's security service said it discovered that Segev made contact with officials at the Iranian embassy in Nigeria in 2012.
The report said Segev was indicted on suspicion of spying for Iran.
A statement issued on Monday, June 18, by the Shin Bet security service said Segev, who was Israel's energy minister from 1995 to 1996, "was recruited by Iranian intelligence and served as an agent".
According to Reuters, the security service said it discovered that Segev made contact with officials at the Iranian embassy in Nigeria in 2012.
Segev was said to have been jailed in Israel in 2004 after being convicted of attempting to smuggle Ecstasy pills. He reportedly left the country in 2007.
The former minister, who "visited Iran twice for meetings with his handlers", reportedly received an encrypted communications system from Iranian agents.
He was accused of supplying Iran with "information related to the energy sector, security sites in Israel and officials in political and security institutions."
The Shin Bet security service also said that the former Israeli minister introduced some stakeholders in Israel's security sector to Iranian intelligence agents, as businessmen.
However, a statement quoted Segev's attorneys as saying that most of the information regarding the indictment remains a secret, as requested by the state.