A320 Captain was informed at FL360 by the A Flight Attendant; that a passenger has been restrained and needs to be removed from the flight; that is done.

Narrative

Shorty after reaching cruise altitude FL360; the A Flight Attendant calls and informs me that a passenger has been tuff cuffed and she will update shortly. First Officer is the pilot flying. A Flight Attendant calls me back to inform me this passenger attacked another Flight Attendant and was being restrained by 2 flight attendants and a passenger. The A Flight Attendant said this passenger is out of control and we should have him removed. Our location is just east of ZZZ. I called Dispatch to inform them of our situation. They agreed that we should land in ZZZ and have this passenger removed. Situation is confined to the rear of the aircraft and is now under control. No emergency is declared; and we do not land overweight. Airport police removed the disruptive passenger. Flight attendants provided a written statement to police. FBI took statements from me as well as the entire crew. Explosives dog searched aircraft and aft lavatory that the passenger used. Maintenance checked all seals in lavatory are intact. Reboarded and departed.When the passenger boarded the flight attendants noticed he was acting a little strangely. During cruise the passenger went to the left aft lavatory. He was in there for a considerable time. He started yelling and pounding on the lavatory walls. Flight attendants investigated; passenger refused to come out. Flight attendants unlocked the door and escort this passenger back to his seat. Prior to sitting down; this passenger turns to strike the Flight Attendant with his elbow. Flight attendants and a passenger restrain and tuff cuff the violent passenger. We diverted and have him removed.