Officials say a decision to bring in external people is the responsibility of schools themselves
Outside organisations that provide sex education to school pupils do not need any qualifications and are not inspected by the Department of Education.
The Oireachtas Committee on Education has this afternoon been hearing from the Department of Education and the National Council for Curriculum Assessment.
It comes amid a 'major review' of Relationships and Sexuality Education (RSE) in schools - with Education Minister Richard Bruton saying he wants to ensure the curriculum "is fit for purpose".
A Solidarity bill to provide 'factual and objective' sex education to pupils is also currently making its way through the Oireachtas.
Addressing the committee today, Rita Sexton from the Department of Education said that while 'outside facilitators' are Garda vetted, the content of any lessons is not scrutinised.
She observed: "The outside facilitators who come into school... no, they are not vetted in terms of the content [...] and they are not required to have any particular qualifications.
"What I would say is that the decision to bring in the external people is a decision made by the whole school, and the board of management would also be involved."
The committee also heard that religious ethos of schools is impacting on the teaching of RSE.
Officials indicated that schools are still relying on a curriculum that is 22 years old, even though some teaching materials are newer.
Department representative Suzanne Dillon said a school's religious ethos can influence how sex education is taught, explaining: "Ethos may well have an impact on how students hear what is being said to them, and how the material is handled.
"We also know that it may be cited by some teachers as preventing them from feeling very confident in dealing with the issues that are there."