A garda who interviewed three children at the centre of a trial involving seven adults accused of various charges of abuse and neglect has told the Central Criminal Court the welfare of the children took precedence over any criminal investigation.

The specialist garda was being cross examined by lawyers for the children's father who faces 34 charges.

The seven on trial include the children's parents, a grandmother, aunts and uncles. All seven deny the charges.

The garda outlined to the court today how she interviewed two of the children in August 2017. The trial heard the interviewer had worked as a full-time specialist interviewer for 12 years.

The garda agreed with Mark Nicholas SC, defending the children's father, that her role was "to facilitate the obtaining of information" from the children and that she was essentially neutral.

Mr Nicholas brought the garda through a 63-page document of guidelines on how specialist garda interviews should be conducted. The document outlines how the child should be able to give a free narrative of the allegations without being interrupted, before open-ended questions are asked, the court heard.

She said every interview was different and the "free narrative" was the child's time to tell what they want to tell.

She was asked by Mr Nicholas if she was aware before carrying out the interviews that the family and the children had been under review of social services for a number of years. She said she was aware that Tusla was involved with the family around the time of the interviews.

Asked if the fact that family support workers had been in the house quite a bit would be of material interest in preparing for her interviews, the garda said her preparation involved judging the children's language and their ability to engage.

She said they were engaged with a social worker and what Tusla had disclosed to them. She said their job was to facilitate the children and they could not influence what a child said in an interview.

She said she was not aware that the children had seen explicit images.

However, Mr Nicholas said an email from a social worker had mentioned indications of inappropriate knowledge.

He said the guidelines suggest that where inappropriate knowledge or language is displayed, efforts should be made to establish the source.

The garda said her role was to facilitate the children to tell their story and she could only go on what they said while being recorded. She said she asked questions to the best of her ability and could not introduce anything they had not said in interview.

Asked if she ever got an opportunity to seek a further interview if more information emerged, she said the welfare of the child "was paramount over any criminal investigation", adding: "They were interviewed twice and their welfare came above anything else".