The Public Accounts Committee (PAC) is taking legal advice on whether it can co-operate with the investigation into penalty points by the Garda Ombudsman.
The Committee has concerns as to whether it can hand over all of its files received from a number of garda whistleblowers.
It is due to hold a private hearing with a serving garda sergeant this afternoon, over allegations of malpractice in the penalty points system.
Laois-Offaly TD Sean Fleming is a member of the Committee. He told Midlands Radio that the meeting today is significant.
The hearing comes despite calls from the Garda Commissioner and the Minister for Justice for it not to go ahead.
The Committee decided on Tuesday night to proceed with its inquiry, which will deal only with the loss to the taxpayer from problems with the penalty points system.
The Garda Ombudsman will meanwhile investigate the allegations of garda malpractice in the cancellation of penalty points and fixed charge notices.