No court in the Commonwealth shall, in any case in which a fine is assessed for the violation of any law of the Commonwealth or any subdivision thereof, assess as a part of the cost of the case any fee for arrest, or as a witness, for the benefit of any law-enforcement officer of the Department; nor shall any Department law-enforcement officer receive any such fee. Any Department law-enforcement officer who accepts or receives any such fee shall be guilty of a Class 4 misdemeanor and, in addition, the Commissioner may remove him therefor. Department law-enforcement officers are not prohibited, however, from accepting or receiving rewards.