Section 51A(1)(b) in The Madras City Police Act, 1888
(b)that witnesses are not willing to come forward to give evidence in public against such person by reason of apprehension on their part regarding the safety of their person or property, the Commissioner may, by an order in writing signed by him, direct such person so to conduct himself as small seem necessary to the Commissioner to prevent such alarm, danger or harm or the commission of such offence, or require such person to move himself outside the said City within, such time as may be specified in the order.