Waikato child sex abuse case 'unbelievable', 'utterly brazen' - High Court judge

A High Court judge has described a Waikato child sexual abuse case as "unbelievable" and "utterly brazen".

Laken Rose, 31, claimed her former partner threatened to kill her if she didn't film him abusing girls as young as three years old.

She faces 50 charges relating to four girls, including rape, indecent assault, and making and possessing videos and photos of sexual acts over a five-year period.

The Hamilton High Court heard on Monday Rose and her former partner Andrew Williams met at an equestrian event when she was 19 and he was 42.

Text messages between them discuss how they will befriend the girls and what they planned to do. Rose would then film Williams offending or film the victims herself for him to see later.

"In my life experience, I can honestly tell you I find it unbelievable that this could occur," Justice Matthew Muir said.

He called the offending "utterly brazen".

Williams admitted 56 charges on day one of the trial after initial denials to police.

"He said, 'who is going to believe a nine-year-old over me', were his words," Crown prosecutor Anna Pollett said.

Defence counsel Philip Morgan QC says Williams was abusive to Rose and she thought he would kill her if she didn't participate.

"She's not there to aid, She's not there to encourage. She's there because that's what he's decreed," he said.

A psychiatrist told the court Rose has dependent personality disorder.

"Because of those personality disorders she's particularly vulnerable to coercion," Morgan said.

Justice Muir said he will give an indication next week of when he hopes to give a verdict for Rose. Williams is set to be sentenced in February.