A retired school teacher has been awarded €88,000 in damages against her former school for harassment and bullying by the then principal.

Bridget Sweeney, 55, a resource teacher from Beaver Row in Donnybrook, took the action against Ballinteer Community School because of the actions of the former principal Dr Austin Corcoran.

Ms Sweeney said she was overlooked for promotion and having appealed the decision, was harassed and bullied.

The court heard she was also followed by a private detective hired by her principal, an incident described as 'truly terrifying' by a High Court Judge.

She suffered depression and had nightmares and flashbacks and retired from her post on health grounds in 2008.

The behaviour of the principal was described by Mr Justice Daniel Herbert as 'oppressive and arrogant'.

He said the court must show its abhorrence of such conduct by awarding aggravated damages to Ms Sweeney. He awarded damages of €75,000 plus special damages of €13,000.

Ms Sweeney had been subjected to a particularly savage form of bullying by being marginalised and 'frozen out' by her principal.

The judge said between October 2005 and September 2006 she was treated in a hostile and dismissive manner after appealing a decision not to appoint her to a post of special responsibility.

The decision by the principal to hire a private detective was described as 'wholly inappropriate'.

While the Board of Management did not know about this at the time, it later decided that he had acted in the course of his duties in doing so and was vicariously liable for his actions.

Mr Justice Herbert found that the Board of Management of Ballinteer Community College - as well as being liable for the actions of its principal - had failed in its duty of care as Ms Sweeney's employer.

The Board ought to have been aware from March 2007 from correspondence from her solicitors, from parents and pupils in the college that she was claiming she was being bullied and intimidated.

The Board should also have been aware that there was a materially serious risk that she would suffer some form of mental illness if the situation between her and the principal continued.

It took no reasonable steps to address the situation. The judge found that on the medical evidence she suffered mental injury in the form of clinical depression as a direct consequence of the deliberate and continuous bullying and harassment by Dr Corcoran.

The issue of costs has been adjourned to a later date.