Harvey Perritt, spokesman for the Training and Doctrine Command, said the action was taken by Gen. Robert W. Cone based on a preliminary investigation by the Army Criminal Investigation Command, Army Times reported. Fort Jackson is in South Carolina.
Perritt said he could not provide details other than to say the investigation pointed to a breach of good order and discipline that was "contrary to Army values and could not be condoned," the newspaper said.
Perritt said the investigation could take another several weeks to several months.
"Regardless of rank or position, soldiers will be held accountable for their actions," Perritt told Army Times. "We have to assume Brig. Gen. Roberts is innocent until proven otherwise."
The newspaper noted an anti-sexual assault and harassment message Roberts had posted to the South Carolina base on the Army's website has been removed.
The message had stated: "Team Jackson, let me be clear, the Army has zero tolerance for sexual harassment and sexual assault, and so do I.
"I view sexual harassment and assault as an enemy threat, and just as we do with other threats, the Army is placing a continued emphasis toward eliminating it. All of us have a shared role in ridding our ranks of this cancerous conduct."
The one-star general was placed in command of Fort Jackson in 2011. An undated Army biography said he is married with three children, the Times said.
Brig. Gen. Peggy C. Combs, commandant of the Chemical, Biological, Radiological and Nuclear School, Fort Leonard Wood, Mo., was appointed interim commander of Fort Jackson, Perritt said.