Plea that acts were done under warrant

Plea that acts were done under warrant. —

1. (1) When any action or prosecution shall be brought or any proceeding held against any police-officer for any act done by him in such capacity, it shall be lawful for him to plead that such act was done by him under the authority of a warrant issued by a Magistrate.
2. (2) Such plea shall be proved by the production of the warrant directing the act, and purporting to be signed by such Magistrate and the defendant shall thereupon be entitled to a decree in his favour, notwithstanding any defect of jurisdiction in such Magistrate.