A defence lawyer for one of five family members convicted of the sexual abuse of a number of children has applied to have some of the verdicts set aside after a member of the jury wrote to the trial judge after the trial.
Five members of the same extended family were found guilty of all but one of the 78 counts against them following a ten-week trial that took place between May and August this year.
They are due to be sentenced in January.
After the trial, a member of the jury wrote a letter to the judge. The contents of the letter cannot be reported.
The defendants in the case cannot be identified to protect the identities of the child victims.
Prosecution lawyers have argued the trial judge had no jurisdiction to set aside verdicts in the case and no authority to contact and question jurors.
Senior Counsel Bernard Condon told the court what happens in the jury room is "absolutely privileged" and there is "absolute secrecy". He said it would now be a matter for the Court of Appeal.
Defence counsel for the children's 27-year-old uncle sought leave to apply to have the verdicts set aside in the wake of the letter from the juror. This was supported by counsel for another of the defendants, the children's 49-year-old uncle.
The three men and two women were found guilty of sexually abusing three children between 2014 and 2016.
They are the parents, aunt and uncles of the children and range in ages from 27 to 57.
The parents were also found guilty of wilfully neglecting five of their children while the father was found guilty of mistreating three of them by giving them medication. All of the defendants had denied all of the charges against them.
Extensive reporting restrictions are in place to protect the welfare and identities of the children, who were taken into care in 2016.
Defene Counsel Conor Devally said that as a result of the letter from the juror, his client is now facing the possibility that "the achievement of the verdicts in his case was unfair or tainted".
"It has left both my client and any objective observer to see that justice has not been seen to be done here," he said.
His client, the children's 27-year-old maternal uncle, was found guilty of eight of the nine charges against him.
He was found guilty of six counts of rape and two counts of sexual exploitation. He was acquitted of one count of sexually exploiting a girl. The guilty verdicts in his case were all majority verdicts.
Mr Devally referred to cases before the European Court of Human Rights in which verdicts have been set aside in similar circumstances and he submitted Irish law is out of date in this area.
Andrew Sexton SC, defending the children's 49-year-old uncle, supported Mr Devally's submissions.
This man - the husband of the children's maternal aunt - was found guilty of all ten counts against him.
He was found guilty of five counts of sexual assault, three counts of sexual exploitation and two counts of rape. Three of the guilty verdicts were majority verdicts.
Mark Nicholas SC, defending the father, said the juror's letter had caused his client "disquiet and concern" and he would support a limited inquiry into the circumstances surrounding the letter. But he submitted that in all likelihood, these inquiries would need to be carried out in another forum.
Mr Nicholas's stance was adopted by Dean Kelly SC, defending the mother and Anthony Sammon SC, defending the aunt.
Bernard Condon SC, prosecuting, said the position of the DPP was that the trial judge had no jurisdiction to set aside verdicts in the case and no authority to contact and question jurors.
Mr Condon said what happens in the jury room is "absolutely privileged". "There is absolute secrecy", he said.
The DPP's position is that this would be a matter for the Court of Appeal, the court heard.
Mr Justice McDermott noted that as far as the trial judge is concerned, once the jury verdicts come in "that's the end of it".
He referred to a British judgment from the House of Lords which ruled the secrecy of jury deliberations must be upheld.
The judge said he would consider the matter and give a ruling on Tuesday morning. The five family members all attended the hearing via video-link.
