(1)When any action or prosecution is brought or any proceedings held against any Police officer for any act done by him in such capacity, it is open to him to plead that such act was done by him under authority of a warrant issued by a Magistrate.(2)Such plea may be proved by the production of the warrant directing the act, and purporting to be signed by such Magistrate; and the defendant in his favour notwithstanding any defect of jurisdiction in such Magistrate. No proof of the signature of such Magistrate shall be necessary, unless the court thinks there is reason to doubt its genuineness:Provided that any remedy which the party may have against the authority issuing such warrant shall not be affected by anything contained in this section.
