Politicians of all stripes have blasted police over their handling of the Roast Busters case, saying changes are needed in how authorities treat victims of sexual violence.
An IPCA investigation released this morning into the case found significant failings in the original police investigations into the group of 17 and 18-year-old men, who boasted online about their sexual exploits with drunk and underage females.
Police began investigating the group in 2011 after girls as young as 13 complained they had been sexually violated, but no charges were ever laid because investigators believed there was no reasonable chance of a conviction.
Social Development Minister Anne Tolley, who was police minister when the Roast Busters complaints were laid, says victims were let down.
"These girls deserved better."
Child, Youth and Family also failed in its handling of the case, she says.
"This whole affair is extremely distressing for the girls and their families - and it must not be allowed to happen again.
"Girls everywhere must have the confidence to come forward and know that any complaints will be taken seriously and dealt with appropriately."
Labour MP Jacinda Ardern highlighted a series of police errors and failings, during an urgent debate in Parliament this afternoon.
Police failed to confront the Roast Busters group and their families over their conduct and should have considered laying charges of sexual contact with a person under 16, she says.
"The police have a lot to do if they want to give security to victims in future that they will handle these complaints adequately."
Human Rights Commissioner Jackie Blue says the police apology over the case is "just the beginning", and more work needs to be done.
"Many sexual abuse victims have also been failed by the current judicial system. I support calls by Justice Minister Amy Adams for the Law Commission to re-start and prioritise this piece of work."
"The statistics are appalling only 10 in 100 sexual assaults are reported to police and only three of them make it to court with only one resulting in a conviction. In other words only 1% of reported sexual assaults in our country result in a conviction."
Police approach failed victims - IPCA
The IPCA's second report into the controversial case says the investigating officers tended to approach each case on an individual, case-by-case, basis instead of developing strategies to reduce the recurrence of what was "clearly unacceptable and, in some cases, criminal behaviour".
Chairman Sir David Carruthers said the Authority believes the officers should have identified the connections between the various cases and worked with other agencies.
"Victims were let down by their failure to do so," Sir David said.
Mr Carruthers said there were deficiencies in the investigation, including a failure to follow up and pursue positive lines of inquiry. He also said the supervisory oversight of the individual cases was inadequate.
"Investigating staff failed to properly consider all available offences in determining whether or not to prosecute the young men."