Huge number of unresolved rape cases revealed

New Zealand faces an epidemic of unresolved rape cases, with thousands of women allegedly sexually abused without justice.

A Herald investigation discovered 2400 aggravated sexual assaults reported to police in 2016 were classified as "unresolved" in 2016 - up to 80 percent of the total figure.

Official data, which Newshub has seen, states there have been almost 14,000 aggravated sexual assaults in New Zealand since 1994. However the true figure is likely to be far higher, due to the way these crimes were categorised.

The Herald found police have been incorrectly coding some difficult-to-prove cases as "K3 - no offence disclosed" or "no crime" instead of "K6 - crime reported".

Police say they have taken steps to address the issue, including "the introduction of a number of new reporting codes that better capture the nuances of sexual assault file resolution".

"Since 2014, use of the K3 designation has dropped markedly; in 2017 only 3.8 percent of adult sexual assault files were given a K3 designation," Police say.

However recent victims of alleged sexual assault told Newshub they are still being let down by police.

Last year, Newshub spoke to a woman called Carol. She says she suffered years of sexual abuse from her former partner who then allegedly raped her twice after they broke up.

She says police didn't treat her with respect when she complained.

"After about three months they sent me an email. The email said that he had been interviewed and he strongly denied the allegations and he was trying to move on with his life and the file was now closed," she told Newshub.

She wanted to discuss the case further, but wasn't told any more information. She says she should have been told the investigation was dropped in person.

She told Newshub she wishes she had never gone to police.

"Because I have all this extra trauma with the way police treated me as well as dealing with the assaults."

Newshub has also learned of another woman's poor experience. After making a sexual assualt complaint, police sent her a letter admitting taking too long to address her case and that the Detective had an "ezy ozy ho hum" attitude towards her.

Police apologised and said it was unacceptable.

The Police Commissioner Mike Bush said they'll always investigate victim's complaints.