Statements received from senior civil servants due to give evidence to the Dail Select Committee of Public Accounts DIRT inquiry, which begins next week, point towards political involvement in the non-implementation of the DIRT law.
The content of some statements so far received by the specially-appointed sub-committee, which will conduct the inquiry, was among the factors which led to it deciding on Wednesday that former ministers for finance would have to be called.
On Thursday, committee chairman Mr Jim Mitchell released the list of 112 witnesses being called to give evidence. The list includes the Fine Gael leader, Mr John Bruton; the former EU commissioner, Mr Ray MacSharry; the former Taoiseach, Mr Albert Reynolds; the Taoiseach, Mr Ahern, and the Labour Party leader Mr Ruairi Quinn - all former ministers for finance. The current Minister for Finance, Mr McCreevy, is not being called as he came into office just shortly before the committee started to examine the issue.
The first witnesses, due to give evidence on Tuesday, are senior civil servants, most of whom are serving or former senior officials in the Department of Finance.
The sub-committee had deliberately "parked" the issue of calling former ministers for finance up to Wednesday, as it was concerned about the creation of party political pressures. But having considered the evidence it has already gathered and statements recently submitted by some witnesses, the sub-committee decided on Wednesday it had no choice but to call the former ministers.
When the sub-committee started looking at the origins of DIRT, why it was brought in and why it was not implemented properly, it became clear that political questions would have to be asked, said a source. Also, statements being submitted by senior civil servants "lead back to the political trail".
The sub-committee also felt that "if we are going to put the Revenue Commissioners through the hoops", it would look very odd if it was not doing the same with the former ministers, said the source.
The hearings, which are to be televised and are expected to last almost five weeks, are being seen as an important development. If successful, they could add prestige to the Oireachtas and allow Dail committees to investigate matters currently inquired into by the vastly more expensive government-appointed tribunals.
For that reason, the sub-committee feels it must show it is capable of inquiring into political matters, even if that involves the danger of creating party political pressures.
Last night the sub-committee chairman, Mr Mitchell, said: "The five former ministers for finance were directed by the sub-committee to appear because it felt it was necessary to ensure a comprehensive review by the subcommittee of the issues in question." He would not comment further.
The Comptroller and Auditor General, Mr John Purcell, produced a report for the committee last month which showed widespread use of bogus non-resident accounts and years of official inaction despite knowledge at the highest levels of the existence of the problem.
Civil servants quoted in the report said it was decided nothing should be done in case action provoked a flight of capital from the jurisdiction. Former ministers were not interviewed by Mr Purcell and there was no direct evidence in the report of government ministers being supportive of the non-implementation of DIRT.
The sub-committee has, as a result of serving an order of discovery, been given all the memorandums to government, cabinet aidememoires and cabinet decisions taken in relation to DIRT in the period 1986 to 1998, the period being investigated.
It has also served orders of discovery on a number of accountancy firms which conducted audits of the main financial institutions.
The evidence from these orders will be additional to the voluminous evidence collected by Mr Purcell.