Pupils from an Upper Hutt Catholic primary school went to a prayer group that included a convicted paedophile and the church never warned the school about the man.
However, St Joseph's parish says it did not tell the nearby school, also called St Joseph's, because the school had no rules in place obliging it to do so.
The parish says the man, who has historic convictions for paedophilia, was under the supervision of a fellow parish member.
Teachers from the Year 1 to Year 8 school were also present at the prayer group, organised by and hosted at the church.
Bill Kirkup, the chair of the parish's pastoral committee, says the church did not disclose the man's past because it didn't have to.
"If the school had had a protocol that said that anybody who had any sort of conviction who was going to work with those children had to have their conviction been made aware of, yes we would have."
The chair of the St Joseph's school board says had the school known, the pupils would not have attended. Mark Petersen says to his knowledge, the pupils have attended the prayer group once.
Mr Petersen says the man concerned has not done anything illegal in the recent past, but should not have been put in a position where he is in contact with children.