Williamson terrorised the Illawarra region for 10 months with a series of brutal sexual attacks against 11 victims, including a five-year-old girl and an 11-year-old boy in 1989 and 1990.

Armed with a knife and wearing a balaclava and gloves, Williamson often broke into homes and attacked his victims or abducted them from their bedrooms or the side of the road.

He served 22 years of a 24-year sentence and was released under strict parole conditions in February 2012, having been denied parole on eight previous attempts.

With Williamson's supervised parole period due to finish next week, authorities sought a court order to continue a raft of conditions, including that he take anti-libidinal medication.

On Wednesday, the NSW Supreme Court made a 28-day interim supervision order, which may be extended, following psychiatric examinations to be conducted by two psychiatrists.

Justice Richard Button said Williamson had not breached parole and lived independently, working part-time, seeing a psychologist, visiting his mother and "living a quiet and abstemious life".

But he said the heinous nature of Williamson's offences meant there was too a high a risk of him reoffending if he was not kept under supervision after his parole expired, and particularly if he stopped taking medication to decrease his sex drive.

Williamson, 44, has taken anti-libidinal drugs since 2004 and says he no longer gets pleasure from fantasising about sexual violence.

But Justice Button said he still had "deep unresolved issues with regard to women" in that "he is uncomfortable with them and professes not to be able to understand them".

The court also heard he continued to be confused about his sexuality. All his victims were female except for the 11-year-old boy but in jail he had an "intimate relationship" with another male prisoner.

He then regarded himself as bisexual and on release from jail he tried to get involved with the gay and lesbian community, but has since changed his mind and sees himself as heterosexual.

Another reason to extend the supervision order was that Williamson suffered a "personal crisis" or "breakdown" shortly after he was released, Justice Button said.

He lived a very isolated life and, apart from contact with his mother and her friends, had very few social connections and almost no-one to fall back on if things started to unravel.

Williamson must wear an electronic bracelet, abstain from alcohol and other drugs and stay away from weapons, pornography and anyone under 18. Any use of the internet or social networks will be closely monitored.

Under his original parole conditions, Williamson was told to stay away from the Illawarra and from his victims.

The interim supervision order says he "must not frequent or visit any place or areas specified by the departmental supervising officer", but does not mention the Illawarra specifically.

It also says he must not contact or communicate by any means with his victims.