In the event of non-compliance with the terms of any notice, order or requisition issued to any person under this Act or any rule or bye-law made thereunder, requiring such person to execute any work or to do any act, it shall be lawful for the Board, or the civil area committee or the Chief Executive Officer at whose instance the notice, order or requisition has been issued whether or not the person in default is liable to punishment for such default or has been prosecuted or sentenced to any punishment therefor, after giving notice in writing to such person, to take such action or such steps as may be necessary for the completion of the act or work required to be done or executed by him, and all the expenses incurred on such account shall be recoverable by the Chief Executive Officer on demand, and if not paid within ten days after such demand, shall be recoverable in the same manner as moneys recoverable by the Board under section 324:
Provided that where the action or step relates to the demolition of any erection or re-erection under section 248 or the removal of any projection or encroachment under section 252, the Board or the civil area committee or the Chief Executive Officer may request any police officer to render such assistance as considered necessary for the lawful exercise of any power in this regard and it shall be the duty of such police officer to render forthwith such assistance on such requisition.