Averment provisions permit an allegation of fact or of mixed fact and law to discharge the prosecutor’s evidential burden. They do not impose either an evidential or legal burden on the defendant and averment by the prosecution, where it is permitted, is merely prima facie evidence of the matters alleged.406 Averment provisions are comparatively rare in Commonwealth law. Section 255 of the Customs Act 1901 (Cth) is a typical, if elaborate, example. It provides that an averment of fact or of mixed fact and law is prima facie evidence of the fact averred. The section states that an averment in a Customs Act prosecution does not alter the burden of proof and has no bearing on the credibility or probative value of evidence given in support or rebuttal of the allegation in the averment. Chapter 2 imposes two limits on the use of averments:
- (a) Fault elements must not be averred; and
- (b) Averments must not be used in prosecuting an offence that carries a sentence of imprisonment.