(1)  A court that sentences an offender to imprisonment for the term of the offender's natural life, either on the conviction of the offender or on the determination of an appeal, must order –

(a) that the offender is not eligible for parole in respect of that sentence; or

(b) that the offender is not eligible for parole in respect of that sentence before the expiration of such period as is specified in the order.

(2)  For the purposes of subsection (1) , a court may have regard to such matters as it considers necessary or appropriate and, without limiting the generality of this, may have particular regard to all or any of the following:

(a) the nature and circumstances of the offence;

(b) the offender's antecedents or character;

(c) any other sentence to which the offender is subject.

(3)  An order made under subsection (1) forms, for all purposes, part of the sentence to which it relates.

(4)  An offender in respect of whom an order has been made under subsection (1)(a) is not eligible to be released on parole in respect of the offender's sentence.

(5)  A court must give reasons for making an order under this section.