New statistics show sexual assault convictions have risen by 27% over five years.
The conviction and sentencing figures from Statistics New Zealand show convictions overall have dropped by 7% over the same period.
A total of 2223 people were convicted of charges relating to sexual offending last year, up from 1748 in 2007.
Justice Minister Judith Collins says that's because more people have the confidence to report sexual offences to police.
She says the rise reflects well on police and the wider justice system because people are trusting them with sensitive information.
Only 10% of victims report sexual assaults to police.
A criminologist at Canterbury University, Greg Newbold, says he would be surprised if the latest figures mean more people are being abused.
He says increased awareness means victims are becoming more confident about coming forward and many historical cases are now being reported.