Patrick Honohan, governor of the Central Bank of Ireland, brought the Oireachtas banking inquiry to life last week with his 3¼-hour appearance in front of the 11 committee members.

In parallel with this, details were emerging of correspondence between the committee, chaired by the Labour Party TD Ciarán Lynch and the department of finance's secretary general Derek Moran in relation to the information being sought by the inquiry as it seeks to unravel the events around the collapse of the financial sector in Ireland in late 2008.

Two letters from Moran to Lynch, dated December 23rd and January 8th, seen by The Irish Times, give an insight into the vast trawl of documents that the committee is attempting to undertake and the resistance and frustrations experienced by those at the receiving end of a direction from the inquiry.

In both letters, Moran makes clear his intention is to “fully co-operate” with the inquiry but he also raises concerns about the volume of material being sought by the committee, the tight timeframe for compliance with its requests for documents and the potential legal issues or sensitivities that exist around some of the information being sought.

“By way of illustration, the department has estimated that the volume of documentation which will be required to be identified, collected, collated and reviewed or prepared in order to respond to the joint committee would run to several hundred thousand pages,” Moran says.

He adds that providing an “unmanageable volume of documentation would not ultimately be helpful to the work” of the committee, which has 12 investigators available to sift through the documents its gets.

It is not just the Department of Finance that is being tapped for documents. All of the main banks, the liquidators of the Irish Bank Resolution Corporation, various auditors and other State institutions, including the Central Bank of Ireland, have also been requested to provide a wide array of material.

The secretary general reminds the committee that the Act does not provide “explicit power” to impose a time limit on handing over documents. “The proposed deadline of January 28th is wholly unrealistic in light of the very broad nature of information sought,” he says.

Moran also questions whether some of the the documents are actually relevant to the committee’s work. This suggests that the inquiry might have been on a large fishing expedition for information. “I would suggest that there are specific areas where there may be a misunderstanding or where a tighter focus would help,” he says in his letter dated January 8th.

“The Solvency II Directive refers to insurance and does not relate to banking. The request would burden the joint committee with a large volume of documentation, which would not be of relevance to its work.

“The reference to Basel III should be replaced by documentation relating to the Fourth Capital Requirements Directive (CRD-IV). This department was not represented on the Basel III committee, which was a committee of central banks.”

Moran has also questioned whether it is necessary to provide email streams concerned only with the scheduling, date and time of meetings or conference calls. The letters indicate that documents have been sought by the committee under more than 100 headings. Moran has sought clarifications in relation to 31 of these areas and has reserved the right not to furnish this information until the committee has clarified its directions.

Requests in relation to changes in legislation on banking regulation and control are described in the department’s letter as “unreasonably broad”.

The clarifications sought in regard to requests for documents relating to the work of the commission led by Finn Peter Nyberg and the report by former Canadian secretary general of finance Rob Wright – both commissioned by the Government to look at aspects relating to the financial crash – are strongly worded.

“This request as drafted would encompass documents in respect of which it would be a criminal offence to provide to the joint committee, pursuant to section 11 of the Commission of Investigations Act 2004,” Moran’s letter states.

"In light of that, I submit that the direction should not encompass the Nyberg commission. In any case, the transcripts and tapes of interviews . . . in respect of the Nyberg Commission. are not within the control of this department."

On the Wright report, Moran highlights how the interviewees were given assurances by the Canadian that their conversations were “off the record” and confidential and suggests that a direction for this material “could adversely impact on future inquiries sought to be conducted on a similar basis”.

Moran has also sought clarification on what the committee means by its requests for documents relating to contrarian views.

“What is the nature of briefing envisaged?” he asks. “Is this briefing provided to the minister or to specific persons in the department? As it currently stands, I submit that this direction should not be made as it is unreasonably vague.”

Moran says he would provide briefing material prepared in response to the contrarian views of economist Morgan Kelly, "but in the absence of such clarity, it is difficult to see how I could adequately respond".

Regarding requests for documents about the EU-IMF bailout programme, Mr Moran said it was “potentially broad and onerous” and suggests the direction should be more targeted.

“Could the joint committee confirm that provision of ‘relevant key documents’ on the EU-IMF programme held by the central policy unit would suffice? In this context, note that this narrower request could still run to over 100,000 pages.”

The issue of Cabinet confidentiality is also raised by Moran, who reminds Lynch that the committee is “obliged” not to direct a person to give it a document relating to a government meeting.

Moran says he will consult the attorney general as to what information he is “lawfully permitted” to release. “I will approach this issue in that spirit and with the intention of minimising any required redactions,” he adds. He also warns that some of the categories could potentially capture commercially sensitive information that would be “irrelevant to the work” of the committee.

It is understood that the committee has yet to provide all of the clarifications sought by the department.

However, the two sides are expected to prioritise certain documentation so that the committee can prepare for the Nexus phase of its inquiry, which will begin in April and involve the main players in the financial drama that played out both before and after the crash giving evidence.