Crown prosecutors are set to seek the strongest sentence possible for a man who raped a Christchurch teenager on two different occasions.

Corey Fowler will today be sentenced on eight convictions, seven of which are of a sexual nature, for the 2015 attacks against a 14-year-old girl.

Fowler entered the girl's room as she slept in July 2015 before raping her.

He then returned again two months later, again raping her and performing other acts against her at knife point.

Crown Prosecutor Claire Boshier has indicated she'll seek a preventive detention sentence for Fowler, due to him having previous sex convictions in the 1990's.