9.20 Lord Bingham has noted that although the presumption of innocence has been recognised since at latest the early 19th century, it has ‘not been uniformly treated by Parliament as absolute and unqualified’.
9.21 Laws reversing the onus of proof have been justified for a few reasons. For example, it is sometimes said to be justified where it is particularly difficult for a prosecution to meet a legal burden. For example, in cases concerning offences against the Migration Act 1958 (Cth) such as Williamson v Ah On (1926), Isaacs J explained that the evidentiary burden will necessarily shift depending on which party has the requisite knowledge and evidence to adduce the truth in proceedings:
The burden of proof at common law rests where justice will be best served having regard to the circumstances both public and private.
9.22 The seriousness of an offence is also sometimes used to justify reversing the onus of proof, particularly where there appears to be a significant threat to the safety of the public.
9.23 Bills of rights allow for limits on most rights, but the limits must generally be reasonable, prescribed by law, and ‘demonstrably justified in a free and democratic society’.
9.24 Some laws reversing the onus of proof may be justified. The ALRC invites submissions identifying such Commonwealth laws that are not justified, and explaining why these laws are not justified.
Sheldrake v DPP  UKHL 43 .
Williamson v Ah On (1926) 39 CLR 95, 113 (Isaacs J).
Ibid 113 .
However, in the South African Constitutional Court, Sachs J said: ‘The perniciousness of the offence is one of the givens, against which the presumption of innocence is pitted from the beginning, not a new element to be put into the scales as part of a justificatory balancing exercise. If this were not so, the ubiquity and ugliness argument could be used in relation to murder, rape, car-jacking, housebreaking, drug-smuggling, corruption… the list is unfortunately almost endless, and nothing would be left of the presumption of innocence, save, perhaps, for its relic status as a doughty defender of rights in the most trivial of cases’: State v Coetzee  2 LRC 593, 677 .
Canada Act 1982 c 11, Sch B Pt 1 (’Canadian Charter of Rights and Freedoms’) s 1. See also, Charter of Human Rights and Responsibilities 2006 (Vic) s 7; Human Rights Act 2004 (ACT) s 28; Bill of Rights Act 1990 (NZ) s 5.