Jofi Joseph, the National Security Council official fired last week for Tweeting secretly under the moniker @natsecwonk, had publicly, albeit anonymously, accused a senior White House official of leaking classified information related to United States intelligence operations against Iran.

Joseph, who was outed in a report Tuesday in The Daily Beast, criticized and insulted dozens of Obama administration officials, lawmakers, Capitol Hill staffers, and journalists during his two-year stint on social media. But his number-one target was Deputy National Security Advisor for Communications Ben Rhodes, a senior official close to President Obama. Rhodes worked for the same department as Joseph, albeit at a much higher level.

In the summer of 2012, Joseph issued multiple tweets under his @natsecwonk account suggesting that Rhodes was the source of classified information leaked to the press about the Stuxnet virus, a joint U.S.-Israeli cyber warfare effort to sabotage Iran’s nuclear centrifuge program. Joseph, as an official in the non-proliferation bureau of the State Department and later inside the White House, was part of the administration’s team working on the Iranian nuclear issue.

On June 14, just days after the FBI began a probe into the leak and the Senate Intelligence Committee started planning public hearings on the matter, Joseph, posing as @natsecwonk, pointed the finger at Rhodes.

“Gotta imagine Ben Rhodes is lawyering up now that a leak investigation is underway. If anyone in the Obama White House leaked, it was him,” he tweeted.

Two days later, as speculation mounted that then National Security Advisor Tom Donilon was a source of the Stuxnet leaks, Joseph again suggested publicly on Twitter that Rhodes was the culprit.

“Folks, even if a National Security Advisor wanted to leak, he wouldn’t be the one doing the leaking. His staff would #keepyoureyeonbenrhodes,” he tweeted on June 16.

Joseph never indicated why he suspected Rhodes or presented any evidence that Rhodes had leaked classified information; a senior White House official close to the Stuxnet leak probe told The Daily Beast that an investigation has not turned up any evidence that Rhodes is implicated. On Tuesday, Joseph told Politico that he regrets “violating the trust and confidence placed in me. He said the account started off as a parody but “developed over time into a series of inappropriate and mean-spirited comments.”

This past June, CNN reported that the FBI was investigating former Vice Chairman of the Joint Chiefs of Staff Gen. James Cartwright in connection with the Stuxnet leak.

Rhodes declined to comment on Joseph’s allegation. Former National Security Council spokesman Tommy Vietor, who worked for Rhodes from 2009 through 2012, strongly disputed Joseph’s claims.

“I sat 10 feet away from Ben for two years and have worked closely with him since 2007. The guy has spent more time trying to prevent the publication of damaging classified information than you could ever imagine,” Vietor told The Daily Beast. “These allegations are flat wrong, and they’re completely ridiculous to anyone who knows Ben and the work he does at the White House.”

Joseph’s tweets about Rhodes were not limited to the senior official’s handling of national security information. The account of @natsecwonk has been shut down, but The Daily Beast has archived records of the tweets, many of which refer directly to Rhodes:

NatSecWonk Did I just hear Tom Donilon bitch slap Jim Clapper? Wow! And then his teenage aide Ben Rhodes piles on… Meow! 8:36 PM Mar 10th, 2011

NatSecWonk Poor, poor Ben Rhodes … madly spinning away, trying to explain a policy that just makes no sense to anyone, right or left. 12:42 AM Mar 24th, 2011

NatSecWonk Hey @erin_pelton - when was the last time Ben Rhodes said something not painfully banal and obvious? What does Obama see in this guy anyway? 1:37 PM Nov 23rd, 2011

NatSecWonk Hey @joshrogin—hearing that some in the WH not very happy with Ben Rhodes’ self-congratulatory and ill-informed Iraq commentary recently! 4:11 PM Dec 18th, 2011

NatSecWonk Apparently, Mr. Rhodes chose to send an email to WH/NSC staff a few minutes before midnight to inform everyone that the Iraq War has ended. 4:13 PM Dec 18th, 2011

NatSecWonk Prepare to be utterly bored: @erin_pelton Deputy Nat'l Security Advisor @rhodesb talks to CBS’s @Norahodonnell on #Syria options and #Iran. 3:27 AM Feb 9th

NatSecWonk @CrowleyTIME It doesn’t help that watching Ben Rhodes mouth banal platitudes at the podium is less interesting than watching paint dry… 2:25 AM Mar 28th

NatSecWonk What’s so disturbing about the Hillary dancing photo is the high-def resolution of Ben Rhodes’ balding pate. And Jake Sullivan behind him. 1:08 AM Apr 16th

NatSecWonk Oh Ben Rhodes, the sad and pathetic life of constantly spinning appears to be getting to you … 11:09 PM Jun 18th

Editor's note: This article has been update to include comment from a senior White House official.