THE Lord Advocate, Lord Hardie, dismissed as ''absolute rubbish'' the claim that the accused in the Balerno killing case were treated favourably by the legal system because they were middle class.

In a wide-ranging interview with The Herald, Lord Hardie also revealed that in the wake of the Scott Simpson murder in Aberdeen a high-powered committee has been set up to investigate how the law can provide increased protection for children from paedophiles.

Questioned about alleged miscarriages of justice in general, and the case of T C Campbell and Joseph Steele in particular, Lord Hardie said he was not aware of any case in Scotland in which he thought a convicted person should not be in prison.

He told The Herald he was considering an appeal against the controversial four-year sentences handed down by Lord Eassie against three youths from Balerno, a middle-class suburb on the outskirts of Edinburgh.

They were originally charged with murdering their 19-year-old victim, but, during the trial, the Crown accepted guilty pleas to the lesser charge of culpable homicide by kicking and stamping him to death.

The Lord Advocate pointed out that to win an appeal against sentence the Crown had to show that the sentence was not just lenient but unduly lenient.

Asked about the Crown's role in the case, he replied: ''I've seen the papers and I'm content that murder was the proper charge. As the father of the victim pointed out in some of his press statements, part of the difficulty was that the evidence didn't come out as expected.

''I think he highlighted the position of the pathologist. Once we were told about the way the evidence had come out, we thought there was really no option but to reduce it to culpable homicide.

''The starting point is that any blow to the head is quite a serious matter and shows an element of recklessness. The difficulty was that when the pathologist was asked in detail about this he indicated that the violence was not severe.

''He had given us a report indicating that it was blows to the head which you would have thought normally would have been a murder case. But once he qualified it and said it wasn't severe violence or severe blows it is quite different.''

That was why the charge had been reduced to culpable homicide, and he rejected the accusation that the accuseds' background had been taken into account.

''That's absolute rubbish. The Lord Advocate operates independently of any pressures and doesn't show fear or favour to anyone. If I had been satisfied that there was a likelihood of a conviction in this case (for murder) we would have gone on.''

Lord Hardie also dismissed as ''nonsense'' the suggestion that the accused would have been treated less favourably had they come from Wester Hailes, the council estate a few miles along the road.

The Lord Advocate agreed that the attitude of the law towards child sex offenders was a crucial issue in the mind of the public.

After the case of Steven Leisk, the paedophile who murdered Aberdeen schoolboy Scott Simpson, the Crown had set up a committee of regional fiscals and Crown Office officials to look at how risk in these cases could be assessed at an early stage.

''In Leisk and a lot of these other cases people say 'You ought to have known that he was a risk. The court ought not to have let him out'. We are looking at what we need to do. I am aware that the public are particularly exercised and quite rightly by this sort of offence but the lynch-mob mentality is not helpful because we can't allow people to take the law into their own hands.''

Lord Hardie said the crux of the problem was identifying at an early stage who would present a serious risk to children in future and assisting the court in evaluating who was at risk of offending again.

For example, if someone appeared in court on ''flashing'' charges would it be possible to pinpoint him as someone likely to go on to commit more serious sex offences? The Lord Advocate accepted that this approach could lead to possible human rights and civil liberties problems, but stressed: ''I think we would be irresponsible if we didn't say: 'What can we do to try to eliminate the risk to children from sex offenders?' We don't sit back and do nothing.''

On the question of miscarriages of justice, Lord Hardie told The Herald: ''I'm not aware of any case where I'm satisfied that they ought not to be in prison.''

He made it clear that, as an independent prosecutor, if he had a concern about a particular case he would bring it to the attention of the appeal court or the Secretary of State. ''I'm not there to keep people in prison whether they're guilty or not. I'm certainly not in the business of keeping people in prison if I genuinely believe that they are innocent.''

He described the so-called ice-cream wars case as a ''horrendous'' murder and added: ''I don't have any concern about the fact that when the appeal was lost they (T C Campbell and Joseph Steele) went back to prison.

''I think the appeal court have got to decide cases on the basis of the law that applies. There has to be some finality to cases as well. You can't have people coming back time and again. Apart from anything else it gives them and their families false hope.''