JERUSALEM (Reuters) -Israel's intelligence agency Shin Bet said it thwarted an Iranian espionage attempt on Friday when it detained and then deported a Jewish Iranian who flew in to the country with a tissue box it said was meant to hide surveillance equipment.

The Shin Bet said the man, who has relatives in Israel, admitted in questioning at Ben Gurion Airport that he arrived in the country to spy on Israeli targets for Iranian security operatives. It said the man, who was found with cellphones, power banks and money, was refused entry and deported back to Iran.

"This event is part of a broad Iranian effort to establish espionage and terror networks in Israel," the Shin Bet said in a statement.

Iran's mission to the United Nations in New York did not immediately respond to a request for comment.

Asked why the suspect was deported rather than prosecuted, a security official told Reuters that, among the agency's other operative considerations, it believed the man was acting under pressure and was motivated by financial gain.

The official added that there was a "low probability" for legal recourse, as the suspect was not an Israeli citizen.

Israel and Iran have been locked in a shadow war for decades, with mutual allegations of sabotage and assassination plots.

According to the World Jewish Congress, there were some 80,000 Jews in Iran on the eve of the 1979 Islamic Revolution, most of whom have left the country since, but the community is believed to still be the biggest in the Middle East outside Israel.

(Reporting by Henriette Chacar; Additional reporting by Dan Williams and Michelle Nichols; Editing by Hugh Lawson)