The man dubbed the "Beast of Blenheim" has had his bid for parole turned down.
The decision on the fate of Stewart Murray Wilson was announced by the Parole Board today, which said he had been assessed as variously posing a high or very high risk of serious sexual or violent recidivism.
Wilson was convicted in 1996 on a raft of sex offences involving 16 female victims over 23 years. The charges included rape, bestiality, stupefying, ill-treatment of children and indecent assault.
He was found guilty on all but two of 25 charges, and sentenced to 21 years in prison.
Wilson had pleaded not guilty to nine rape charges, one attempted rape charge, six indecent assault charges, two cruelty to children charges, two assault charges, one bestiality charge, two charges of attempting to drug to take advantage, and two charges of drugging women for sex.
The board said Wilson's lawyer, whose name was withheld, had anticipated it would be imposing conditions today to take effect on Wilson's final release date of December 2.
"We are not prepared to do so," the board said.
"Mr Wilson has been assessed as variously posing a high or very high risk serious sexual or violent recidivism. In those circumstances it is essential that he have a robust release proposal. He has not."
The board said it would see him again in November for the imposition of release conditions.
But Wilson may stay behind bars if a special order under section 107 of the Parole Act 2002 is made.
Some offenders sentenced before July 2002 may only appear before the board once, and that is to set their release conditions.
Offenders in this category (serious violent offenders) are required to be released after serving two thirds of their sentence, which is known as their final release date.
Release is not discretionary with the Parole Board's only role being to impose conditions.
However, under section 107 the chief executive of the Department of Corrections may apply to the board for an order that an offender be kept in prison beyond their final release date.
Offenders subject to orders under section 107, or section 105 of the Criminal Justice Act 1985, must have the order reviewed at least once every six months.
The law changed in 2002, allowing the board to hold an offender in prison until the end of their sentence.
In 2006/07 there were 20 section 107 hearings, of which 95 per cent (or 19) were approved.
There were 92 reviews of section 107 orders, of which 93.5 per cent (or 86) were approved.
In 2007/8 there were 21 section 107 hearings, 20 approved.
There were 102 reviews in 2007/8, 100 were approved.