The civil servant behind the Ansbacher dossier has requested to give evidence at a hearing of the Dail's spending watchdog.
Department of Jobs official Gerard Ryan has sought a private hearing with the Public Accounts Committee (PAC), the Irish Independent has learned.
He is seeking a similar arrangement to that used to allow garda whistleblower Maurice McCabe give evidence of abuses of the penalty points system.
The high-profile committee held an "in camera" hearing for Sgt McCabe last year and although a transcript was never published, the evidence was taken into account in the PAC's damning report on the fixed charge processing system.
In a letter to the committee, Mr Ryan said he wished to respond to evidence given last month by Revenue Commissioners chairperson Josephine Feehily, who denied a number of allegations he made in the dossier.
Mr Ryan had investigated Ansbacher as an authorised officer between 1998 and 2004.
In a dossier he gave to members of the committee last November, he linked several former government ministers with the Ansbacher offshore tax-dodging scheme.
He claimed evidence of these alleged links was not properly investigated by several state agencies over the course of the past decade.
Mr Ryan also alleged political interference took place to ensure the evidence was not followed up.
However, Ms Feehily disputed this and said all of Mr Ryan's leads had been fully investigated.
She also said she had never encountered any political interference in the work of Revenue.
Members of the committee are expected to decide today whether to call Mr Ryan.
It is understood a number of committee members would prefer if Mr Ryan made a written submission rather than giving oral evidence.
The committee could then consider whether or not to put all or part of it on the public record.
Their reluctance stems from uncertainty over whether or not Mr Ryan qualifies for whistleblower status and how evidence he gives can be treated.
Committee members were given legal opinion by Oireachtas lawyers last night advising against the calling of Mr Ryan as a witness and warning of potential pitfalls if he is allowed give evidence.
The serving civil servant has previously written to the committee stating he had received legal advice that he was fully covered by new protected disclosure legislation when he passed the dossier to its members.
However, Oireachtas legal advisors say they believe he does not qualify for protection.
If this turns out to be the case, Mr Ryan could find himself open to legal proceedings from those identified in the dossier.
Using Dail privilege, Sinn Fein deputy leader Mary Lou McDonald stated former Fianna Fail ministers Ray MacSharry, Maire Geoghegan Quinn and Gerry Collins, former Progressive Democrats leader Des O'Malley, former Fine Gael minister Richie Ryan and an "S Barrett" had been named in the dossier.
All quickly denied ever holding Ansbacher accounts. The family of the late former minister Sylvester Barrett also denied he had ever held such an account.
Last month, Ms Feehily said Revenue officials were "quite surprised" by Mr Ryan's claims.
She insisted any information provided by Mr Ryan "was fully examined and followed up wherever it took us."