The Revenue Commissioners now had the power of access to banks like any other company irrespective of whether there was any suspicion of wrongdoing, the PAC was told.
Mr Pat Rabbitte TD (Lab) said the Revenue had in the past been obliged to treat the financial institutions differently and did not have the power to go in unless there was wrongdoing.
Mr Donal McNally, assistant secretary at the Department of Finance, said: "They can get in the door now. The position now regarding access is in line with regular tax-payers generally."
He said the position whereby the Revenue could not get access had changed as a result of the 1999 Finance Act, although it was "not completely unfettered".
Earlier, the Minister of State at the Department of the Taoiseach and Chief Whip, Mr Seamus Brennan, before the PAC on its recommendations on parliamentary and procedural reforms of the Oireachtas, said he agreed with the committee's call for urgency.
"We are looking to put together a parliament of the 21st century, and the committee system is an essential part of that," he said.
The Clerk of Dail Eireann, Mr Kieran Coughlan, said Ireland was bottom of the league as regards staff and resources in the parliament as compared to other EU countries.
Senator Joe O'Toole, chairman of the review group on auditing, said the report would be in PAC's hands in three weeks.