A man wants the High Court to quash a finding by Tusla that allegations of "sexual impropriety" made against him by a former foster daughter were "well founded".
The man denies the allegations and says that the findings are unreasonable, fundamentally flawed, and have caused great distress and upset in his life.
On Monday at the High Court, Mr Justice Seamus Noonan heard the allegations were made by a teenage girl to her social worker during the course of a car journey in mid-2014.
During the course of the conversation with the social worker, the girl claimed she was sexually harassed by the man while she had been living with him and his family as a foster child some years previously.
Counsel for the man Paul Gunning Bl said the claim against his client had never been "stress tested".
The girl was not interviewed by Tusla and the finding was based on that one conversation, counsel said.
The DPP did not bring a prosecution against his client, counsel added.
In 2015 Tusla informed the man, whom they interviewed, the teen's complaint was well founded.
Mr Gunning said the findings were appealed. The appeal ultimately upheld the original finding.
Counsel said the appeal was flawed because his client was not given a proper and full appeal on the merits of the case.
Mr Gunning also said that because of this finding, his client and his family have had to agree that he not have any unsupervised access to his grandchild.
If this was not agreed to, there was a risk the Child and Family Agency might take action and have the grandchild taken into care, counsel said.
His client is a qualified care assistant who works at a facility with vulnerable adults, counsel said.
Following the findings he was reassigned to maintenance duties.
The man's lawyers were given permission to bring the challenge against both Tusla and the two members of the independent appeal panel, by Mr Justice Noonan.
It was granted on an ex-parte (one side only represented) basis and comes back to court in May.