All agents or inspectors of the Board or Division, peace officers, and the Attorney General, district attorneys and their deputies while investigating violations of the provisions of NRS 453.011 to 453.552, inclusive, in performance of their official duties, and any person working under their immediate direction, supervision or instruction are immune from prosecution under the provisions of such sections for acts which would otherwise be unlawful under such provisions but which are reasonably necessary in the performance of their official duties.
NRS 453.551