1. A person is not relieved of criminal liability for conduct because he or she engages in such conduct under a mistaken belief of fact or law unless such mistake negatives the existence of the mental state required by the offense.
2. A person is not relieved of criminal liability for conduct because he or she believes his or her conduct does not constitute an offense unless his or her belief is reasonable and:
(1) The offense is defined by an administrative regulation or order which is not known to him or her and has not been published or otherwise made reasonably available to him or her, and he or she could not have acquired such knowledge by the exercise of due diligence pursuant to facts known to him or her; or
(2) He or she acts in reasonable reliance upon an official statement of the law, afterward determined to be invalid or erroneous, contained in:
(a) A statute;
(b) An opinion or order of an appellate court; or
(c) An official interpretation of the statute, regulation or order defining the offense made by a public official or agency legally authorized to interpret such statute, regulation or order.
3. The burden of injecting the issue of reasonable belief that conduct does not constitute an offense under subdivisions (1) and (2) of subsection 2 of this section is on the defendant.