LONG term sickness at a school embroiled in a row between staff and management has cost the public purse more than half a million pounds in five years.
De La Salle College racked up sick leave costs of more than £270,000 between 2010 and last year.
The total bill for the 2014/15 financial year - £87,410 - was higher than any other secondary school in the north.
Sickness expenditure also increased significantly between 2014 and 2015.
The figures reveal, however, that this issue pre-dates the appointment of the current principal and board of governors.
The west Belfast school has been in turmoil over a breakdown in relations between some of the 70-strong staff and principal Claire White for several months.
It has seen pickets by parents and pupils amid fears that summer exams will be affected.
Teachers undertook a rolling sick day protest last year when up to 15 staff called in sick on four separate days in one week. Staff members were said to be concerned about an incident that took place in October last year and how it was handled.
The relationship between some staff and management appeared to sour further and teachers again started calling in sick as parents began a daily protest outside the school.
Parents said long-term sick leave was a growing problem at the school.
An analysis of the school's resources and expenditure by the Irish News reveals that the cost of long-term staff sickness has been high for years, however.
Leave of more than 20 working days is considered long-term. The cost of this is met by the Education Authority. Substitute teacher costs for absences up to 20 days comes out of the school's own budget.
Ms White was appointed head of De La Salle in June 2014.
In the 2014/15 financial year, sickness leave at De La Salle totalled £87,410, higher than any other post-primary school for which figures are available.
The school also had some of the highest total sick leave costs in both 2013/14 and 2012/13 - £66,712 and £80,781. Figures for 2015/16 are not yet available.
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Long-term sick leave costs 2014/15
De La Salle, Belfast £87,410
St Louise's, Belfast £85,212
Holy Cross, Strabane £71,645
St Patrick's, Maghera £60,938
St Cecilia's, Derry £60,253
Magherafelt High £53,742
Dunclug, Ballymena £49,981
St Genevieve's, Belfast £41,453
Bangor Academy £40,730
Omagh High £39,110
