(CNN) -- A major general who formerly headed U.S. Army operations in Japan will be forced to retire and do so at a lower rank after the military concluded that he failed to "properly address" sexual assault allegations in his command, the Army said on Wednesday.
Army Secretary John McHugh has directed that Maj. Gen. Michael T. Harrison "be retired" as a brigadier general, according to a statement.
The Army said federal law requires that officers retire "at the highest grade" at which they served satisfactorily and McHugh determined that in Harrison's case, it was one step below his current rank, the statement said.
An Army investigation found that Harrison mishandled sex assault allegations reported to the command, Lt. Col. Alayne Conway said. No other details were provided.
Harrison was suspended from his post as head of U.S. forces in Japan last year amid the investigation.
The military has struggled with the issue of sexual misconduct reports within its ranks.
Under current guidelines, military commanders have the authority to decide whether their subordinates should face prosecution when such allegations emerge.
A debate in Congress over whether to remove that decision-making process from the command structure was the subject of political infighting earlier this year.
Harrison joined the Army in 1980 served in numerous capacities around the world. He is due to retire in October.