A jury at the Central Criminal Court has heard it was not credible that several members of a family had abused a number of children in their home while they were under intense scrutiny from social workers.

Closing arguments from the defence have been continuing in the trial of five family members accused of the abuse of three children.

Today the jury heard closing submissions from defence counsel Dean Kelly SC, who represents the children's mother.

Mr Kelly told the jury there was scarcely a detail of the children's lives that were not the subject of scrutiny from a social worker and a family support worker during the time they were alleged to have been repeatedly sexually abused.

"This was a house that could not have been less free from the scrutiny of the agents of the State and yet it was the house that was the seat of these horrors. I suggest this is unbelievable," he said.

He said there was never a concern about physical, emotional or sexual abuse despite one family support worker being in the house so often that she was "almost part of the family", he said.

He said the prosecution was alleging there was a family circle in which the most awful sexual violence was carried out.

"You are asked to believe that all of these people came to this house and these children to inflict their depraved intentions where they would almost be passing social workers at the gate as they came and went and you must ask yourself how credible is that? How could it have happened under the nose of that level of scrutiny?"

He said the house was almost like one in a TV programme "with a police helicopter shining a light on it" in terms of the scrutiny it received from social workers and yet that was what the prosecution was asking the jury to believe.

He said the accounts of the children about the allegations of sexual abuse lacked real physical reality and the prosecution had invited the jury to forget about the "downright incredible nature of some of the allegations".

He said the admissions made by the mother in her Garda interviews would not be the first time an innocent person had admitted to something they had not done.

He outlined a number of cases to the jury where this had happened and one where a false allegation had been made by a child.

He asked the jury not to ask themselves why would a child make something like this up.

"Put that to one side, it gets you nowhere and is an exercise in speculation," he said.

Mr Kelly said while gardaí said their interviews had been adapted to account for his client's mild intellectual disability they had not done so "one jot".

If they had, alarm bells would have gone off and they would have seen the red light of caution when she started to make admissions in her sixth interview.

He said she had admitted to things the children had not complained of or that were bizarrely impossible and gardaí should have been on the highest alert when this happened.

Instead, he said, they "took the admissions, dropped them into the evidence bag and drove on".

He said the charges of criminal neglect against the children's mother were "nonsense", pointing out that she had deprived herself of soap, toothpaste and toilet paper as well as the children.

Her own hygiene was just as poor and there was no deliberate or cruel neglect of her children in this regard, Mr Kelly said.

He said a social worker said she had made the application to take the children into care "with a heavy heart", which is not something she would have said if there had been deliberate and wilful neglect, he said.

He told the jury his client was "an inadequate mother and a hopeless parent" which she would have to live with for the rest of her life but these were not matters which should impinge on their consideration any more than the horror they had felt when they first heard the allegations.

In facing the monstrous and shattering allegation the only way to do so was to focus on the detail and substance and to "go in with your sleeves rolled up and a willingness to explore things that should cause you disquiet and cannot be pushed to one side".

He said the allegations remained shrouded in confusion and doubt and in circles that did not close and they had a duty to bring in verdicts of not guilty for his client.

Earlier, counsel for the children's father told the jury the only evidence they really had of sexual activity had come from the children and there was nothing clear or unambiguous about the evidence.

He said there was evidence that the children had access to pornography but this had not been properly investigated or explored in their interviews with gardai.

Mark Nicholas said this was not a normal family background or dynamic, "there was no control, no supervision, no respect, no boundaries. There was strong language and fighting in front of social workers and family support workers. They were not putting on a show."

He said it was known there was pornography "floating around" and it was never investigated and the jury would have to ask if the allegations were "lived experiences or something they may have seen somewhere else".

He said the nature of the allegations would have meant brutal assaults and yet the children never described them in such terms and said others present did not say anything.

He asked if this was credible.

He said despite the numerous professionals who spent time in the house and with the children and who were specialists in child protection, they "suspected nothing, saw nothing, sensed nothing" in relation to allegations of sexual abuse.

He said the children were taken into care for reasons of neglect and that never changed.

The children had no boundaries and were reported to be sexualised and yet teachers reported no such behaviour in the yard or classroom, he said.

He also reminded the jury that as a matter of law what one of the other accused may have said happened could not be used when assessing the case against his client.

Mr Nicholas asked the jury not to treat it as a slam dunk of a trial and to assess the evidence carefully.

Those on trial include the children's parents, uncles and an aunt.

They face a range of charges relating to the abuse and exploitation of three children.

The parents are also charged with wilful neglect.

All charges are denied.

There are wide-ranging reporting restrictions in place by order of the court to protect the children's identity and for their welfare.