Where an officer takes any action in pursuance of instructions of the Commissioners or a Collector of Customs and Excise given in connection with the enforcement of the enactments relating to general betting duty, bingo duty or the duty on F1. . . F2amusement machine licences and, apart from the provisions of this section, the officer would in taking that action be committing an offence under the enactments relating to betting or gaming, he shall not be guilty of that offence.