The convicted rapist dubbed the Beast of Blenheim is likely to appeal a decision subjecting him to a 10-year supervision order once his parole conditions end.
Justice Graham Lang ruled on Friday that Stewart Murray Wilson, who was jailed for 21 years in 1996 for sexual offending against women and girls, was a rare and special case who would be at risk of offending against young females well beyond the expiry of his release conditions.
The 65-year-old, who was sentenced before preventive detention laws were introduced, is due to be released from prison on September 1 and must be released despite being assessed as being at a high risk of reoffending.
The Parole Board's strict release conditions expire in September 2015, after which the 10-year supervision period commences.
Wilson's lawyer Andrew McKenzie says Wilson would be disappointed at Justice Lang's decision and he expected his client to appeal.
"Mr Wilson's had a long term of imprisonment. He feels he's done his time and obviously his age is such that such an order's probably going to see his days out," Mr McKenzie told Radio New Zealand.
Justice Lang's ruling came after the Corrections Department pressed for an extended supervision order, saying Wilson was at high risk of reoffending and the public needed to be protected.
At the hearing clinical psychologist Jane Freeman-Brown supported the extended supervision order, saying Wilson, who continues to deny his offending, is at high-risk of reoffending.
But Mr McKenzie said the court should have waited until near the time his parole conditions ended before making a ruling to see how he handled his release.
Wilson will have a Parole Board hearing next month to set out his release conditions.