The man, who entered Israel using his Belgian passport under the name of Alex Mans, was arrested at Ben-Gurion International Airport on September 11 as he was attempting to return to Europe.
Photographs of the US embassy in Tel Aviv and of other sites in Israel were found among his possessions.
According to the officials, he admitted to receiving orders from Iranian agents, after being recruited by the paramilitary Iranian Revolutionary Guards and was promised one million US dollars for his services.
He also named four of his Iranian handlers, one of whom is described as a senior operative with the Qods (Jerusalem) Force, the foreign operations arm of the Revolutionary Guards.
Mans was said to have visited Israel three times over the past year using his Belgian passport and tried to create business ties and contracts with Israelis in Tel Aviv, the officials added.
Born in Iran in 1959 as Ali Mansouri, Mans lived in Turkey from 1980 but moved to Belgium in 1997, where he received citizenship in 2006.
The arrest was initially placed under a gag order.
Iran has been an implacable foe of Israel since the Iranian revolution in 1979 that brought a radical Islamist regime to power.
Recent overtures of moderation by Iranian President Hassan Rowhani have been labelled a "ploy" by Israeli Premier Benjamin Netanyahu.
Iran, which had previously made numerous threats against Israel, is accused of developing nuclear weapons by Israel and the West.
Israel too is thought to possess such weapons.
Voice of Russia, AFP