Despite being behind bars for more than four years, Regan Philip Burrell’s progress had been "limited", a psychologist said.
The 23-year-old Rolleston Prison inmate is serving a total sentence of more than six years and accepted he would be declined early release at a hearing last month.
"We are far from satisfied that he meets the test for parole," panel convener Martha Coleman said.
When Burrell was a teenager, he targeted two 12-year-olds and a 13-year-old, one of whom he locked in the back of his vehicle after convincing her to meet him in a carpark.
He threatened to kill her dogs if she told anyone about what had happened.
At the 2019 sentencing, the court heard Burrell approached his victims online before luring them into meetings during which he committed the sex acts.
One victim only met up with him because he repeatedly made threats about distributing nude photos to her friends and family.
He repeated the blackmail five times, the court heard.
Months after his sentencing, Burrell was awaiting dinner in his cell when he called out to another inmate whom he regarded as a "snitch".
He had earlier filled a one-litre container with boiling water and when the man came to his cell, Burrell poured the water over his face and right arm.
He also doused the prisoner with a cup of tea and later admitted he wanted to hurt the victim as much as possible.
Burrell later pleaded guilty to injuring with intent to do grievous bodily harm.
While locked up, he had completed a child-sex-offender programme but a psychologist said it had had little impact.
"Comments in the report from him are said to indicate a (continued) callous disregard for his victims and a view of them as sexual objects," the Parole Board heard.
"This indicates that there is considerable work that Mr Burrell needs to do on his attitude to women."
In July, Burrell was removed from a specialist sex-offender group course but would work individually with a clinician to complete its "core treatment phase".
Ms Coleman also noted the man required further treatment to address his propensity for violence.
One of the victims told the board about the ongoing harm that Burrell’s crimes continued to cause.
Ms Coleman said when Burrell was released, it would likely be on condition that he not enter the Clutha, Dunedin and Waitaki districts.
Burrell will appear again before the Parole Board in August, three months before his sentence expiry.
