Following the not guilty verdict in Lorraine Stirling’s case, her union, the Educational Institute of Scotland, called for a change in the balance of power, saying there was an assumption that pupils are automatically telling the truth.

But child protection experts expressed concerns that a consequence of high-profile cases might be to persuade children and other vulnerable groups that they would not be believed.

Miss Stirling, from Dollar, Clackmannanshire, who has 30 years’ experience of teaching, had been accused of pinching the skin of pupils, pulling their hair and hitting them with books and rulers.

In a three-day trial at Alloa sheriff court, Miss Stirling’s headteacher said he had received a warning from one child that other boys and girls were “getting together and making up stories”. The court was also told that the allegations came to light after a persistent truant claimed that “fear” of Miss Stirling was preventing her from going to school.

Sarah Nelson, a specialist writer and Edinburgh University researcher on child protection, who served recently on a Scottish Executive working party on sexual abuse, said: “While one is reluctant to comment on individual cases, there is concern about the general principle that in cases involving certain groups - child witnesses, children from a difficult background, witnesses who have been in prison or psychiatric patients - they are vulnerable to claims being made that they have invented their stories.”

She added: “If a conspiracy is being claimed in court, there really needs to be sound evidence.”

Anne Houston, director of Childline Scotland, said: “Children are aware of what is happening - they read the newspapers and watch the news - and court cases can have an impact on them. They draw their own conclusions and that can make it more difficult for them to feel able to come forward.”

Ms Houston added: “Young people are increasingly encouraged to report any kind of abuse but large numbers of children still don’t do so. It is vital that we continue to reinforce the message to children that they should talk to someone they trust if they have a problem.”

She quoted the case of 14-year-old “David” (not his real name), who said:

“My teacher hit me over the head with a jotter. He’s done it to other people too. I told the headteacher but he didn’t believe me. My dad didn’t believe me either.”

However, Judith Gillespie, development manager of the Scottish Parent Teacher Council, who has been lobbying hard against what she sees as overzealous enforcement of disclosure checks on parent volunteers, called for people to exercise a “little more sense of judgment”.

“Sometimes kids tell the truth and sometimes they lie,” Mrs Gillespie said.

“I hope that the child protection zealots will back off and can get back to a slightly more sensible perspective. Everything is becoming far too extreme - we have got to a point where children are becoming dangerous for any adult to have anything to do with.”

Margaret McKay, chief executive of Children 1st, said that research suggested children were no more likely to lie as witnesses than adults and when they did it was for the same reasons - because they were afraid or because they wanted to protect someone they trusted.

However, she added: “Where there are cases of clear infringement of the law they should be pursued. Our concern is that what is being called child protection is not child protection at all. It is about people being able to say: ‘Thank goodness I’m covered’.”

Ronnie Smith, general secretary of the EIS, echoed that concern, suggesting there was now a greater readiness on the part of police and fiscals to run cases through to a conclusion, inspired perhaps by a fear of repercussions and being the person who draws the line and says that a case will not proceed any further.

Mr Smith said that the union’s employment relations committee was likely to be discussing ways of changing the law to extend the legal anonymity of a complainant to a teacher - unless the accused person was found guilty.

“As things stand, protection is given to the complainers and absolutely no protection to the person complained against,” he said.

Miss Stirling must have gone through purgatory but because of the publicity the whole country had shared in her ordeal.

“She can’t walk down the street without people saying: ‘That’s her.’ But the kids, who might appear to have been engaged in an unpleasant conspiracy to ‘do in’ a teacher, have absolute immunity and anonymity. It is almost a case of power without responsibility, and it’s unbalanced.”