Developments this morning:

Police reveal four girls complained about Roast Busters
Three complaints were made in 2011, one last year
Waitemata District Commander not aware of complaints
Police Commissioner summoned to Beehive
IPCA asked by Minister to investigate

Police Minister Anne Tolley says she would be "extremely disappointed'' if police had not followed strict protocols when questioning a young complainant in the Roast Busters case.

Mrs Tolley was asked about the police investigation into the Roast Busters group by Labour's police spokeswoman Jacinda Ardern during question time in Parliament this afternoon.

Mrs Tolley announced earlier today she had referred the police handling of the Roast Busters case to the Independent Police Conduct Authority after meeting Police Commissioner Peter Marshall this morning.


She had asked the IPCA to investigate it, in particular the police questioning of the 13-year-old girl in 2011.

"Parents of young girls need to have confidence that complaints to Police about sexual assault are investigated thoroughly and appropriately,'' she said.

In Parliament this afternoon, Ms Ardern asked whether police questions about the complainant's clothing would imply that what the girl was wearing could influence the case.

"I really think that we should stop jumping to conclusions,'' Mrs Tolley responded.

"The police have very strict protocols around the investigation of sexual assault charges and allegations. It is my expectation that police will adhere to those.''

She said police had worked hard in recent years to raise their performance and focus on victims' needs.

"And I would be extremely disappointed if they had not lived up to those standards. That is one of the reasons that I have taken this so seriously; that I have taken the unprecedented step of referring this to the IPCA for investigation.''

Labour MP Carol Beaumont asked what had been done to warn young women in west Auckland about the actions of the group, given their "predatory nature and well-signalled plans to target young women''.

Mrs Tolley said she had been assured by Mr Marshall that the police investigation had been "thorough and enthusiastic''.

Police had interviewed the young men on numerous occasions, and had spoken to their families and schools.

"But without any evidence they cannot make unsubstantiated accusations about young people.''

Mrs Tolley reiterated that she had confidence in police, but a number of questions have been raised about the investigation, which was why she had written to the IPCA today.

"The public of New Zealand need to have confidence that police take allegations of sexual assault extremely seriously, and that they will do all that they can to ensure perpetrators are held to account.''

Mrs Tolley said both herself and Mr Marshall had only become aware of the formal complaint last night.

This morning, she told Mr Marshall she was disappointed they had not been properly briefed. Mr Marshall and the district commander were now looking into why the information was not available to them.

During today's meeting with Ms Tolley, Mr Marshall gave her a broad "overview'' of the complaints that had been made.

He was confident the IPCA investigation would confirm police had done their best in relation to the inquiry.

"I also want to make clear in relation to that first formal complaint, it was taken to its natural conclusion - it was investigated to the extent nominated people were interviewed and there was not the evidential threshold in relation to that particular matter.''

Police wanted to speak again with the other three young women complainants, but so far the parents of two of the alleged victims had told police to stay away from their daughters.

"We understand that position and we will do whatever we can.''

Four complaints made to Police

Today's meeting between Mrs Tolley and Mr Marshall was in the wake of revelations that four girls had approached police with complaints about the Roast Busters.

Police confirmed three were in 2011, and one was made late last year.

In a statement emailed to media this morning, police said only one of the four complaints was 'formal', "where an official statement was made by way of an evidential video interview".

Last night a girl told 3News she complained in 2011 when she just 13-years-old about being sexually assaulted by two young men.

She said the line of questioning centred on the clothes she was wearing and why she had chosen to go out with the group.

Waitemata District Commander Bill Searle has apologised to her this morning and said he was unaware a formal complaint had been made.

Until last night, police had said they had been unable to bring prosecutions against the young men because they were yet to receive a formal complaint by any victims.

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Police had been monitoring the Roast Busters for the last two years, who bragged online they would ply girls - some as young as 13 - with alcohol and have sex with them.

Their activities came to light this week with media reports, and the Facebook page they boasted on was shut down.

Waitemata District Commander Superintendent Bill Searle tried to explain to Radio New Zealand why the girls' complaints were not taken further.

"These are very difficult cases and not only do we have to satisfy the law and to satisfy the law we have to have evidence, but we also have to apply the Solicitor-General's guidelines which give clear guidelines as to when we can prosecute matters."

- Police launch own investigation of complaint handling -

Mr Searle said he was distressed with the suggestion by one complainant that police questioning of her was inappropriate.

"I'm conducting a review of the case and we'll look very carefully about what was said and done by the police officers dealing with this girl.''

Police would supply different officers to the original investigating officers for future interviews, he said.

Even though the behaviour was "immoral and repugnant'', police had to deal with evidence, Mr Searle said.

"If there's not evidence to the standard required, we cannot progress that to court.''

Sometimes, even if there was a formal complaint, there might not be enough evidence to take the case to court, he said.

Earlier this week, police said their hands were tied without a formal complaint by a victim.

Mr Searle said police appreciated it was difficult for young girls to come forward in cases of a sexual nature.

"However, it is an important component of the overall evidence and does contribute to the overall evidence if these girls do come forward and provide statements.''

Mr Searle said he would cooperate with any inquiries that were launched into the police handling of the case, after Labour MP Jacinda Ardern last night said she would refer the case to the Independent Police Conduct Authority.

- Action being taken against group -

After the activities of the Roast Busters were revealed this week, two members presented themselves to police for interviews.

As a result of that, police had executed a search warrant, Mr Searle said.

"Some items have been seized, which we're currently analysing and we're hoping that will contribute to the inquiry.''

- 2011 complainant "angry" -

When asked if the complaint by the 13-year-old in 2011 was one of rape, Mr Searle told Newstalk ZB that it depended on lots of bits of legislation.

"It's about some sexual activity that the girls are not happy with, and based on the legislation we'll see which legislation is the most appropriate.''

The girl, now 15, interviewed by 3News said she was angry no charges were laid.

She was left traumatised, and after she plucked up the courage to tell her family two weeks later, her parents took her to police to lay a complaint.

"I had a video interview where I had to act out what had happened with dolls ... it was traumatising."

The girl felt it was her word against the Roast Busters. Her brother also gave police the names and addresses of the youths involved.

- Superintendent not aware of complaints, apologises -

Mr Searle told Radio Live that when he was originally briefed on the Roast Busters investigation he was told no original complaint had been laid.

"To be honest I now find that there was a formal complaint and there's no doubt that that was a formal complaint.

"All I can do is apologise to the victim in question because it would only possibly have caused her extra stress and I'm very sorry about that.''

Mr Searle said he was looking into why he wasn't told about the original complaint and why the complaint wasn't taken any further.

Mr Searle told TV3's Firstline that over the next few days he would find out why he was given the incorrect information.

He refuted a suggestion there was a "culture of disbelief'' of sex victims within the police.

"I think what's happened here is the police officers have done their very best and we'll need to see if their very best was good enough or we'll need to do better.''

Police had been in the process of recontacting the victims over the last couple of weeks, "to see if we could take it any further'', he said.

Evolving story

Sunday: Detective Inspector Bruce Scott said there was nothing police could do until a girl was "brave enough" to make a formal complaint.

Monday: Mr Scott said no girl had made a formal complaint.

Tuesday: Superintendent Bill Searle said none of the girls from the original inquiry wanted to make a formal complaint.

Yesterday: A teenage girl says she made a formal complaint to the police two years ago.

This morning: Police confirm four girls have now laid complaints with police about the Roast Busters.