Aggressive rather than passive legislation which is as concerned with consumers as with prudential regulation is what the financial sector requires, the Tanaiste told the Dail.
She also told TDs that 13 inquiries were under way in the Department of Enterprise, Trade and Employment.
Some institutions were co-operating and others were not and that was the reason why the reports were taking so long to prepare.
Ms Harney said there was a need to enforce existing regulating legislation. "One of the disappointments of recent times is that in many respects existing regulation in company law is not enforced," she said, answering questions on recent financial scandals.
Given the controversies which have arisen and the advent of the euro there was a need to be more concerned with consumer interests, Ms Harney said. "And to a large extent that does not require new laws but a new attitude and a new culture.
"There is an undeniable case, in a small country such as ours, for building a critical mass of skills related to financial regulation within a single body."
A working group she established in September to look at the enforcement of company law is due to report in days. That group is looking at the need for change.
Ms Harney told the Fine Gael deputy leader, Mrs Nora Owen, that the 13 inquiries included 10 investigations under Section 19 of the 1990 Companies Act into Celtic Helicopters, Garuda Ltd, Irish Intercontinental Bank Ltd, Guinness & Mahon (Ireland) Ltd, Kentford Securities Ltd, Ansbacher (Cayman) Ltd, Hamilton Ross Co Ltd, Faxhill Homes Ltd, Dunnes Stores Ireland Company and Dunnes Stores (ILAC) Ltd.
The two Dunnes Stores inquiries are the subject of judicial review and the hearing of that review is expected to start this week.
The report on an investigation into Bula Resources (Holdings) Ltd, has been sent to the DPP, the Central Bank and the Garda Bureau of Fraud investigations.
Ms Harney said she was concerned at the number of investigations - 13 inquiries and two tribunals of inquiry.
However, "I think it is preferable that we carry out the inquiries and that we take whatever action is necessary rather than simply avoid taking decisions because we might be concerned about criticism of the length of time or the waste of public money or whatever."
She added: "We don't use that view when it comes to street crime and I don't think we should take that view either when it comes to matters of that kind."
On appointing a single regulatory body she said the Central Bank looked after financial institutions to ensure they remained stable. "I don't think it is fair to expect a body which is supposed to protect institutions on the one hand to also be the same body that goes in to take action on behalf of the consumer," she said.
"The conflict of responsibility that the Central Bank has may be part of the problem and that's why we followed the route of establishing an implementation group on which the Central Bank is represented."
Ms Harney told Mr Tommy Broughan (Lab, Dublin North East) that she had no responsibility in relation to the banking industry but did for the insurance industry, credit unions and friendly societies.
"The difference between AIB and NIB, and I have to stress this, is that we have responsibility for insurance and the breaches that occurred in NIB related to the insurance industry. NIB was selling products that they had no authorisation to sell in the Republic of Ireland and that was a serious breach of the insurance legislation." The AIB controversy was a tax-related matter and the responsibility of another Minister.
Ms Harney added however, that "recently a person sent me documentation in relation to AIB and I did forward that to the gardai and the Central Bank and to the Revenue and others".