18. The Act of 2006 is amended by the insertion of the following section after section 3:

“3A. (1) A person in authority who engages in a sexual act with a child who has attained the age of 17 years but is under the age of 18 years shall be guilty of an offence.

(2) A person who attempts to commit an offence under subsection (1) shall be guilty of an offence.

(3) It shall be a defence to proceedings for an offence under this section for the defendant to prove that he or she was reasonably mistaken that, at the time of the alleged commission of the offence, the child against whom the offence is alleged to have been committed had attained the age of 18 years.

(4) Where, in proceedings for an offence under this section, it falls to the court to consider whether the defendant was reasonably mistaken that, at the time of the alleged commission of the offence, the child against whom the offence is alleged to have been committed had attained the age of 18 years, the court shall consider whether, in all the circumstances of the case, a reasonable person would have concluded that the child had attained that age.

(5) The standard of proof required to prove that the defendant was reasonably mistaken that the child had attained the age of 18 years shall be that applicable to civil proceedings.

(6) It shall be a defence to proceedings for an offence under this section for the defendant to prove that he or she has reasonable grounds for believing that he or she was not a person in authority in relation to the child against whom the offence is alleged to have been committed.

(7) It shall not be a defence to proceedings for an offence under this section for the defendant to prove that the child against whom the offence is alleged to have been committed consented to the sexual act of which the offence consisted.

(8) A person guilty of an offence under this section shall be liable on conviction on indictment to imprisonment for a term not exceeding 10 years.”.