The letters do not select any one individual out for criticism, and are directed at the organisation rather than any named person working in or for the scouts.
It follows several weeks of controversy after it emerged in several reports by The Irish Times, that Mr Elliott had provided a report to the board of Scouting Ireland earlier this year into how a rape allegation was handled by the organisation.
Minister for Children Katherine Zappone has said in recent days that she was suspending funding to Scouting Ireland until she was happy with governance issues raised in Mr Elliott's critical case review report.
A barrister has also been appointed to follow up on the issues raised by Mr Elliott in his review.
In the first of the letters which Mr Elliott wrote to Scouting Ireland, on 27 February, RTÉ understands that Elliott raised a major concern over the manner in which all the information he felt was needed to conduct this review was not provided to him.
After giving Scouting Ireland an initial report into the matter, he says he learned that some meetings had occurred between persons in the Scouts and the person who was accused of abuse, but that these meetings did not come to Mr Elliott's attention and they were not recorded on the case file which he had been asked to review.
In this letter of 27 February, Mr Elliott wrote to Scouting Ireland to say he wanted that initial report to be withdrawn and amended after he says he learned that he was not in possession of all the facts.
He questioned whether the organisation had a full understanding of what disclosure meant.
It is understood that Mr Elliott also says in the correspondence that all of his work was agreed to be carried out under strict confidentiality.
He questions whether some people had actively set out to put this information into the public domain and he makes it clear that this makes it harder for him to do his job, in the face of the inevitable comment on the issue, which he is not then in a position nor allowed to respond to or deal with in public.
Mr Elliott says this is a very serious matter.
He says that he was asked to undertake a review under strictly private and confidential terms.
He says that he has been placed in a position outside of his control where he cannot place his trust in the organisation in relation to the confidences that were asked of him but which he feels were not observed by others in the organisation.
Again, he does not name any names of any members in this regard but expresses considerable frustration about how details of his work ended up in the public domain.
While Mr Elliott is engaged in other ongoing work with the Scouts on the safeguarding front, it is understood that he says in the correspondence that he is not going to continue to engage in any further open communications with the organisation in relation to the critical case review on the basis of this breakdown in trust and confidence as he describes it.
Mr Elliott was not available for comment.
Scouting Ireland did not comment when contacted on Mr Elliott's contacts over the issue.
A barrister is currently undertaking a review of safeguarding issues raised in Mr Elliott's critical case review and her work is expected to be done in the coming weeks.
Scouting Ireland is expected to write to and seek a meeting with Minister Zappone on this issue in the coming days, at which they will set out a plan agreed at the Scouts national conference yesterday.
Scouting Ireland agreed to convene an Emergency General Meeting in the summer which could facilitate enhanced governance structures within the scouts.
The Oireachtas Committee on Children and Youth Affairs is also eager to explore these issues and has invited Scouting Ireland to appear before the committee.
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