Two recent news items in different newspapers on the same day revealed contrasting points of view between judges and politicians with regard to the operation of the national register of offenders who are convicted for sex offences against children.

It was reported in The Age on August 20 that a Victorian County Court judge had been very critical of the fact it was unavoidable that an offender who had pleaded guilty to offences against children had to be placed on the sex offender register for life when there was no chance that he would reoffend.

Judge Lisa Hannan sentenced the offender to a 12-month community-based order, and suggested that the registration requirement was a ''travesty'', and that there should be judicial discretion in cases like this.

These are strong words to come from the Bench as most judges are reluctant to make public statements which could be seen as critical of the government which appointed them and which creates the legislation they are required to follow. Off the record, however, many judges will make similar comments. On exactly the same day, this newspaper carried a headline ''Govt eyes tightening laws for sex crimes'' in which it was reported that the ACT Government, on the advice of the Ombudsman, proposed making the requirements of the sex offender register more stringent with sentences of up to five years for not complying with reporting obligations. There was no mention of any consideration being given to judicial discretion.

This news item was informative as it explained that the Child Sex Offender Register which had been in force in the ACT since 2005 and was surrounded by a strict secrecy regime. The register holds information on the identities and whereabouts of ACT residents who have been convicted of sexual offences against children and those guilty of child pornography offences.

The secrecy surrounding the sex offender register means that the public cannot know how many cases are on the register at any time nor what offences were committed. Furthermore, official reports on this subject are usually marked on every page ''Law enforcement in confidence''. That is fairly intimidating and I am not even sure if I am allowed to say whether or not I played a role in the preparation of one of those reports.

Regardless of that, I can certainly say that for over half a century I have taken an interest in this subject and have spoken to scores of sex offenders in prisons, and have also attended many conferences, seminars and expert meetings on sex offending and the treatment of sex offenders. In 2006 I even wrote a lengthy report for the ACT Government Sentence and Release Options for High Risk Sexual Offenders.

It is from this breadth of experience and discussion that I have come to the conclusion that the sex offender register is not working as it should. I have no doubt that when the relevant legislation was passed it was done with the best of intentions. The aim was clearly to deter the worst offenders who target children, but the result is the labelling of thousands of people who are reported to, or detected by, the police for engaging in sexual behaviour with children under the legal age of consent.

This used to be known as carnal knowledge and, as Judge Hannan made clear, it is against the law and should be punished appropriately, but it is not appropriate for these offenders to be classified as paedophiles and placed on a register so that they can be monitored for the rest of their lives.

The misuse of the sex offender register stems from the fact that not many people seem to understand the very significant differences between paedophilia and the precocious sexual behaviour of teenagers. Paedophiles are generally mature adults who are obsessed with particular groups of very young children, pre-pubescent girls or young teenage boys for example.

Their thinking is generally strategic, and they may spend many months ''grooming'' their targets. They have even been known to pursue single mothers in orders to gain access to their children. Paedophiles also nearly always treasure photographs and video clips of children in the age and gender groups that they prefer.

Hence they have active ''paedophile rings'' which exchange images of children, whether those children have been targets or not. In fact a significant minority of paedophiles are passive in they only want to view child pornography without seeking any contact with the children themselves. (Passive paedophiles are still serious offenders, however, as they create the market for much of the abuse of children.)

Finally, paedophiles are quite different from other sex offenders in that they tend to cluster in particular occupational groups or work situations. They are also more likely than others to move interstate or overseas if they perceive any danger of arrest. For these reasons they are less likely to be listed on the sex offender register than are less serious offenders.

In my opinion the operation of the sex offender registration system is in need of thorough review at a national level so that it can focus on the offenders who are most dangerous and not those whose behaviour is closer to the norms of this society. And while they are at it, the review might address the issue of the duplication of services which result in offenders like the young man sentenced by Judge Hannan being supervised by police and community corrections officers at the same time.

In the interests of increased productivity, which applies to the public sector as much as it does to the private sector, two agencies doing virtually the same job is a clear waste of money and manpower.

David Biles is a Canberra-based consultant criminologist.