In 1991 Diane Watson, 16, was murdered by fellow pupil Barbara Glover in the playground of Whitehill Secondary School in Dennistoun, Glasgow.

Glover had taken a knife to school with the expressed intention of attacking Diane.

Later that year, at the High Court in Glasgow, Glover, then aged 15, was found guilty on two counts: an unprovoked assault on Diane on April 9, 1991 and the murder of Diane on the April 10, 1991. She was ordered to be detained without limit of time.

Diane's parents, Margaret and Jim, and their son Alan, were devastated by the killing and nearly 18 months later Alan took his life. He was found with press cuttings in his hand, including articles from The Herald by columnist Jack McLean.

Mr and Mrs Watson have no doubt that these articles, published when this newspaper was under different ownership and editorial control, contributed to their suffering and to Alan's death.

The columns sought to highlight what Mr McLean believed to be the harsh treatment of children within the judicial system. It was an issue he felt very strongly about but in addressing it he caused offence and misrepresented important aspects of this case. In particular the Watsons took exception to the following:

The first article, dated August 2, 1991, appeared to condone Glover's behaviour by suggesting it was an acceptable part of working-class culture to carry and use knives. The article sought to reinforce this suggestion by describing the mandatory life sentence as extraordinary but did not mention that for those under 18, like the defendant, the normal sentence served is usually less than 10 years.

The same article made a distinction between Diane's background and that of the girl who murdered her and it suggested Diane had treated Glover with snobbish disdain. This was untrue, although Mr McLean insists it was not his intention to imply such behaviour. But there was no evidence that Diane treated her in that way or that the origins of their respective families were in any material way different.

The article also suggested the murder was an incident which could have happened anywhere where class and territory are important. But this was not a murder committed in a sudden fit of anger. The murder was unprovoked and planned. Glover had told friends she was going to attack Diane.

In his second article, published on June 26, 1992, Mr McLean repeated the false suggestion of a class distinction between the murderer and the victim and sought to attract sympathy for Glover by drawing an analogy with the case of a middle-class student defendant, accused of a stabbing, against whom the case was found not proven.

In his third article, of December 11, 1992, Mr McLean criticised Michael Martin, the MP who had supported the Watsons, in an article published on the day of their son Alan's funeral. The article sought to reinforce the misleading picture he painted of Diane's murder.

Following the publication of these articles, the first of which was published when this title was still named The Glasgow Herald, Mr and Mrs Watson asked for a meeting with Mr McLean and senior colleagues. They found the outcome of this meeting - held weeks after it was requested - unsatisfactory.

This is an extraordinary and tragic case for all those involved and we believe its exceptional nature requires exceptional steps to be taken by The Herald. That is why we are publishing this article today.

The Herald and Times Group deeply regrets any actions which added to the Watson family's grief over the loss of their daughter Diane and later their son Alan and apologises unreservedly for them and for the misrepresentation of Diane's true character.

The columns were published some 20 years ago under different ownership and Mr McLean has not worked for this company for many years.

The Herald and Times Group is committed to the highest quality of journalism and accuracy in its reporting and analysis. We are regulated by the Independent Press Standards Organisation (Ipso) and adhere to the Editors' Code of Practice.