According to VIC Law for the charge of Sexual penetration of 16 or 17 year old child,

Crimes Act 1958 - SECT 48

Sexual penetration of 16 or 17 year old child

48. Sexual penetration of 16 or 17 year old child

(1) A person must not take part in an act of sexual penetration with a 16 or 17 year old child to whom he or she is not married and who is under his or her care, supervision or authority.

Penalty: Level 5 imprisonment (10 years maximum).

(2) Consent is not a defence to a charge under subsection (1) unless the accused satisfies the court on the balance of probabilities that at the time of the alleged offence the accused believed on reasonable grounds-

(a) that the child was aged 18 or older; or

(b) that he or she was married to the child.

(3) If consent is relevant to a charge under subsection (1), the prosecution bears the burden of proving lack of consent.

(4) For the purposes of subsection (1), and without limiting that subsection, a child is under the care, supervision or authority of a person if the person is-

(a) the child's teacher;

(b) the child's foster parent;

(c) the child's legal guardian;

(d) a minister of religion with pastoral responsibility for the child;

(e) the child's employer;

(f) the child's youth worker;

(g) the child's sports coach;

(h) the child's counsellor;

(i) the child's health professional;

(j) a member of the police force acting in the course of his or her duty in respect of the child;

(k) employed in, or providing services in, a remand centre, youth residential centre, youth justice centre or prison and is acting in the course of his or her duty in respect of the child.

According to VIC Law for the charge of Sexual penetration of 16 or 17 year old child,
10 years

(a) The accused committed an indecent act or was party to the commission of an indecent act with or in the presence of a 16 or 17 year old child.

(b) The accused was not at the relevant time married to the child.

(c) The child was under the care, supervision or authority of the accused.

(d) The accused acted wilfully.

(a) Consent.

(b) Factual dispute.

(c) Identification dispute.

(d) Lack of intent.

County Court.