A White House staffer has been fired for being the man behind a mysterious Twitter handle that sent out vulgar and insulting messages directed at top politicians, both Republicans and Democrats.

Jofi Joseph, who worked in the non-proliferation section of National Security, was behind @natsecwonk, a Twitter feed infamous within Washington that had been running since February 2011. However, it was suddenly shut down last week. Two administration officials confirmed to The Daily Beast that Joseph was the writer of the tweets and has been fired. He was also working on negotiations with Iran.

According to The Washington Post’s source, the White House did launch an investigation to try to find out who was @natsecwonk, but it’s not known if this is how the administration ultimately found out.

Joseph’s @natsecwonk handle sent out messages that were openly critical of White House policies and would insult State Department officials by name. “Was Huma Abedin wearing beer goggles the night she met Anthony Weiner? Almost as bad a pairing as Samantha Powers and Cass Sunstein,” he wrote in one tweet, insulting a Clinton official, a Congressman and White House officials in one 140-character message.

CBS News notes that tweets also criticized Republicans. “Look, (Rep. Darrell Issa, R-Calif.) is an ass, but he's on to something here with the @hillaryclinton whitewash of accountability for Benghazi,” he wrote about the House Oversight Committee chairman.

The New Yorker notes that many of the worst insults sent by Joseph were insulting to women, particularly their bodies. “[Liz Cheney is ] what happens when rank nepotism meets sheer stupidity. Also, she takes after her father -- she's like 30 pounds overweight,” he wrote in one. Another read, “Who are the two blondes flanking [Chelsea Clinton]? And is it just me, or has she put on some weight?”