One of the country's largest primary schools is among a number of State multi-denominational schools that have outsourced teaching about relationships and sexuality (RSE) to a Catholic agency.
Data received by RTÉ News shows that three Education and Training Boards around the country have contracted Catholic marriage agency ACCORD to deliver RSE programmes at a number of their schools, paying the organisation more than €10,000 out of State funds over the past two years.
They include Scoil Choilm Community National School in west Dublin, which caters for more than 800 children.
Last year, Dublin and Dún Laoghaire ETB paid ACCORD €1,142 to give classes on puberty to children at the school.
RTÉ News understands that the children were separated into two groups according to their gender for the sessions.
The school is categorised as multi-denominational.
ACCORD was established more than 50 years ago by the Catholic bishops with a central aim of supporting Catholic marriage.
Scoil Choilm's Relationships and Sexuality Education policy states that content "of a sensitive nature", including "the naming of private body parts" and "sexual development", will be delivered by an external guest speaker, not the class teacher.
The policy says fifth and sixth class children will spend one full school-day each at these outsourced sessions, during which they will learn about what the policy calls "the sensitive issues".
The policy stipulates that the children will be divided into two groups, male and female, for the one day workshops.
As well as paying ACCORD to deliver the workshops at Scoil Choilm, Dublin and Dún Laoghaire ETB also paid an additional €1,961 to ACCORD to deliver RSE workshops at Lucan Community College.
A second-level DDLETB school, Coláiste Pobail Setanta in west Dublin, paid €340 to ACCORD for classes last year.
Kildare-Wicklow ETB paid ACCORD €4,857 for RSE workshops in a number of its schools over the past two years.
Louth-Meath ETB paid ACCORD €3,765 over the same period.
Solidarity-People Before Profit TD Ruth Coppinger, who represents the Dublin West constituency where Scoil Choilm is situated, told RTÉ News that she saw no justification for an ETB using a religious organisation to deliver Relationships and Sexuality Education, particularly to a school like Scoil Choilm which is in a multi-ethnic and multi-religious area.
She said a lot of parents in the constituency would have sent their children to Scoil Choilm thinking that they were getting an alternative to Catholic education.
Ms Coppinger, who has tabled a bill calling for reform of sex education in schools, said of particular concern was the fact that ACCORD did not promote or affirm LGBT relationships.
Relationships and Sexuality Education is mandatory in schools.
While Catholic-run schools frequently outsource the delivery of RSE education to ACCORD, none of the schools in question here is Catholic.
They are all State-run schools categorised as multi-denominational.
The payments from Kildare-Wicklow ETB include one of €1,448 for workshops given at St Kevin's Community College in Dunlavin, Co Wicklow.
A similar sum was paid for RSE programmes in Coláiste Chraobh Abhann in Kilcoole, while ACCORD was also paid for workshops and talks given at Piper's Hill College in Naas, and Glenart College in Arklow.
The agency was paid €1,056 by Louth-Meath ETB to deliver a "Full Year Programme" at Dunshaughlin Community College.
Just over €1,600 was paid for delivery of two "RSE Programmes" at O'Carolan College in Nobber. The ETB paid ACCORD €1,080 for RSE workshops and a talk entitled "Insight into Adolescence" at Coláiste De Lacy in Ashbourne.
The review will include an examination of the role of the classroom teacher in teaching the curriculum as well as "supports which are currently being provided by external providers".