Defense Secretary Ash Carter Removes Top Aide Over Alleged Misconduct

— -- Defense Secretary Ash Carter announced today that he has removed one of his top military advisers due to allegations of misconduct.

"Today I made the decision to remove my Senior Military Assistant Lieutenant General Ron Lewis from his position after learning about allegations of misconduct," Carter said in a written statement.

Carter did not immediately explain the alleged misconduct and a Pentagon official familiar with the issue cited legal limitations that prevented the Defense Department from discussing it further. Lewis had been serving as Carter's senior military assistant.

Carter said he has referred the incident to the Pentagon Inspector General for further investigation and said "the Department of the Army will then take action as appropriate."

Meanwhile, Lewis has been temporarily assigned to the Army Vice Chief of Staff's office pending the outcome of the investigation, officials said.

"I expect the highest possible standards of conduct from the men and women in this department particularly from those serving in the most senior positions. There is no exception," Carter wrote in his statement.

A statement from a spokesperson for the Inspector General's office confirmed an investigation had been launched, but did not provide details.

"The Department of Defense Inspector General received a referral from the Office of the Secretary of Defense regarding the senior military assistant to Secretary of Defense Ash Carter," the IG's office said in a statement. "The DODIG will conduct an investigation."

A West Point graduate, Lewis served three tours in Iraq and Afghanistan as an Apache attack helicopter pilot and squadron commander.

When Ash Carter became defense secretary earlier this year, he tapped Lewis to be his senior military officer based on the close working relationship they developed when Carter served as deputy defense secretary.

After Lewis was promoted to the two star rank of major general and serving as the Army’s chief of public affairs, Carter’s move led Lewis to be promoted yet again so he could fill the role of senior military adviser, which requires a general officer of three-star rank.

A senior Defense Department official said Carter was made aware of the allegations of misconduct on Tuesday evening and that he was "very surprised" to hear it.