The current s44 offence came into force on 5 August 1991, replacing the former offence of incest under s52.
The amendments to s44 extended the offence to include the children, lineal descendants and step-children of an accused’s de facto spouse.
The current offence applies to any acts committed on or after 5 August 1991 (Crimes Act 1958 s585A(2)).
If an offence is alleged to have been committed between two dates, one before and one on or after 5 August 1991, the offence is alleged to have been committed before 5 August 1991 (Crimes Act 1958 s585A(4)).
The offence as enacted in 1991 included a defence of coercion. Section 8 of the Crimes (Sexual Offences) Act 2006 repealed with defence and replaced it with a new defence of compulsion. The new defence applies to offences alleged to have been committed on or after 1 December 2006 (Crimes Act 1958 s606A). These defences are discussed below.
There are four main elements to the offence of incest:
The accused must have taken part in an act of sexual penetration with another person;
The sexual penetration must have been intentional;
The parties must have been in a prescribed family relationship;
The accused must have known about that relationship.
Where the question of voluntariness is in issue (e.g., where the accused alleges that he or she was asleep at the time the act was performed), the jury should also be instructed that the act of penetration must have been conscious, voluntary and deliberate (R v MG (2010) 29 VR 305). See Voluntariness for further information.
Intentional sexual penetration
"Sexual penetration" is defined in s35 of the Crimes Act 1958. See Rape for information about this definition.
Under s35(2), the person who sexually penetrates and the person who is penetrated are both deemed to be "taking part" in an act of sexual penetration. This means that an accused may be found guilty of incest whether they were sexually penetrating or sexually penetrated.
It also means that both parties to an act of sexual penetration may be liable to prosecution for the offence of incest. It has been held that it is not appropriate to class a complainant as an accomplice in incest cases (R v Ware 10/3/1994 SC Vic).
The sexual penetration must be intentional (R v AJS 13/12/2005 CA Vic).
Prescribed family members
The four family relationships prescribed by s44 are:
The children, step-children or lineal descendants of the accused (s44(1));
The children, step-children or lineal descendants of the accused’s de-facto spouse who are under 18 years of age (s44(2));
The parents or lineal ancestors of the accused, where the accused is over 18 years of age (s44(3));
The siblings or half-siblings of the accused (s44(4)).
Adopted children are deemed to be the children of both their natural parents and their adoptive parents for the purposes of s44 (Adoption Act 1984 (ss53(1) and (2)).
Section 35 of the Act defines ‘de-facto spouse’ as “a person who is living with a person of the opposite sex as if they were married although they are not”.
Applying this definition in the context of incest contrary to section 44(2) requires the jury to consider the nature of the relationship between the accused and the alleged de-facto spouse.
As part of this assessment, the jury may consider whether the accused exercises any parental responsibility for the children of the alleged de-facto spouse, including:
(a) the role played, and responsibility assumed, by the accused with respect to the child(ren);
(b) the authority exercised by the accused over the child(ren); and/or
(c) the view which the child(ren) and the accused respectively had of the nature of the relationship between them (Sutton v R (2015) 47 VR 496, ).
A marriage-like relationship can exist even where its sole purpose is to provide support for the children (Sutton v R (2015) 47 VR 496, ).
Due to the statutory context of the offence of incest, the relationship between the accused and his or her partner’s children is likely to be more significant in determining whether a de-facto relationship exists than in cases involving the distribution of property (Sutton v R (2015) 47 VR 496, ).
However, in general, it is undesirable for judges to expand on the statutory definition of “de-facto spouse” as the statutory definition calls for the jury to apply its common sense and experience to evaluate the relationship of the parties and compare it to their understanding of marriage relationships. This allows the jury to accommodate varied and even conflicting concepts of marriage-like relationships. Providing a list of factors relevant to assessing whether the relationship is marriage-like risks impermissibly interfering with the jury’s assessment of what makes a relationship marriage-like (Sutton v R (2015) 47 VR 496, ).
Knowledge of the family relationship
Except for offences under s44(2), the accused is presumed to know that they are related to the other person in the way alleged. This presumption can be rebutted by evidence to the contrary (s44(7)(a)).
Where it is necessary to prove that particular parties were married, there must be strict proof of the marriage. It is not sufficient to rely solely on admissions of the accused as to the marriage, or on evidence of co-habitation or common repute (R v Umanski  VR 242).
Consent is not a defence to a charge of incest (s44(5)).
Old scheme – Coercion defence
Where the offence is alleged to have been committed prior to 1 December 2006 it is a defence for the accused to prove on the balance of probabilities that he or she was coerced to take part in the act of sexual penetration (s44(6)).
New scheme - Compulsion
The Crimes (Sexual Offences) Act 2006 substituted a new s44(6) & (6A) which replaced "coercion" with a defence of "compulsion".
For offences alleged to have been committed on or after 1 December 2006, a person will not be guilty of the offence of incest if he or she was compelled to take part in the act of sexual penetration (Crimes Act 1958 s44(6)).
The definition of compulsion was modified on 28 November 2007. Section 44(6A) now defines compulsion as follows:
For the purposes of this section, a person compels another person (the victim) to take part in an act of sexual penetration if the person compels the victim (by force or otherwise) to engage in that act without the victim's consent.
These amendments apply to "any trial commenced on or after [28 November 2007] irrespective of when the offence to which the trial relates is alleged to have been committed" (Crimes Act 1958 s609(1)).
Despite the absolute terms of s609(1) it is doubtful that it applies the new compulsion defence to offences committed before 1 December 2006. The 2008 amendments operated solely to delete qualifications to s44(6A). They cannot operate to insert the positive aspects of s44(6) and s44(6A) into the Act at a time prior to the date of their substantive enactment. While in practice this provision is most likely to be considered in trials where the compelled party is the uncharged victim of the offence, it can be expected that s44(6) will be raised as a defence by defendants.
It is likely that if raised on the evidence, this is a defence that the prosecution must disprove beyond a reasonable doubt (see R v Mark & Elmazovski  VSCA 251; R v Deblasis (2007) 19 VR 128).
Other Relevant Matters
Depending on the circumstances of the case, the trial judge may need to consider the following issues in relation to incest cases:
Accomplice warnings (but see R v Ware (10/3/1994 SC Vic), in which Coldrey J held, after a review of the authorities, that it was not appropriate to class a complainant as an accomplice in an incest case);
Possible exemptions from being compelled to give evidence in a case involving certain family members (Evidence Act 2008 s18);