Aynsley Harwood can rest easy for a while after her child's killer was denied his freedom this week.

But she feels obligated to continue the fight to keep him behind bars for as long as it takes.

"I will always have to think about it. I feel if I didn't I wouldn't be a good mother."

Child killer Peter Joseph Holdem, 51, was rejected in his first hearing before the Parole Board in three years.

It is 21 years since Holdem abducted 6-year Louisa Damodran off a Christchurch street as she walked home from school, allegedly molested her, gagged her and threw her in a river where she drowned. At the time, he had just been released from prison for the attempted rape of a 10-year-old girl, and had a history of sexual offending against other children.

The death of her daughter has taken a heavy toll on Ms Harwood's life, but the decision to keep Holdem in prison this week came as a great relief.

"We had a very small celebration. A friend and I had a couple of bowls of icecream.

That was our celebration."

"Louisa had a lot of friends and I think she would have wanted to protect other children."

The board said Holdem's crime was appalling and shocked the nation.

He understood the views of his victims "and he accepts the anger and despair and outrage which lie behind them".

"The psychological report we have received shows him still being at high risk of sexual and violent offending. There have been no treatment gains for him. There is a very poor prognosis for his future. He has had a number of interventions over the years but nothing which has diminished his risk of reoffending."

Ms Harwood said as a Christian, she had "a very slim hope he may reform".

"I believe in miracles. And I believe it will have to be a miracle."

Conscious of the effect of parole hearings every year for Holdem's victims, the board will in November consider postponing his next hearing for two or three years.

Former police detective inspector Mal Griebel, who caught Holdem, told Newstalk ZB yesterday he was delighted Holdem had been unsuccessful in his bid for freedom. He says he has no doubt Holdem would have killed again if he had been released.

Mr Griebel described Holdem as evil and said he was pleased for the future of other girls that Holdem remains behind bars.