An FBI translator was sentenced to 20 months in prison last year for leaking secret US wiretaps of the Israeli embassy to a blogger, the New York Times reported on Tuesday.
Prosecutors and even the judge were tight-lipped about the case, the first of a record five prosecutions of individuals who leaked information to the press during President Barack Obama's administration.
But the Times said, based on the first interview with the blogger in question, Richard Silverstein, that contract Hebrew translator Shamai Leibowitz had leaked documents related to sensitive US efforts to spy on a close ally.
Silverstein, who runs the liberal Jewish blog "Tikun Olam: Make the World a Better Place," said Leibowitz had passed along some 200 pages of verbatim phone records because he feared an Israeli attack on Iran and was concerned about Israel's efforts to lobby the US Congress and the American public.
The Times said it was not able to fully corroborate Silverstein's account, and US and Israeli embassy officials could not immediately be reached for comment.
Silverstein, identified as "Recipient A" in court records, said he had burned the documents when Leibowitz came under investigation in 2009.
He recalled, however, that the conversations included discussions among American supporters of Israel, embassy officials and at least one member of Congress.
Silverstein told the Times he had decided to speak out to make it clear that Leibowitz, who was prosecuted under the Espionage Act, had noble motives.
"I see him as an American patriot and a whistle-blower, and I'd like his actions to be seen in that context," the Times quoted Silverstein as saying.
"What really concerned Shamai at the time was the possibility of an Israeli strike on Iran, which he thought would be damaging to both Israel and the United States."
Both Israel and the United States have refused to rule out a military strike on Iran to halt its nuclear enrichment program, which they believe is aimed at producing weapons, charges denied by Tehran.
The Times quoted experts as saying it is common knowledge that the United States spies on Israel despite the two countries' close military alliance.
The Obama administration has taken an especially strong line against officials who divulge information to journalists, bringing a record five prosecutions under the Espionage Act.