Former International Monetary Fund deputy director Dr Donal Donovan has said he has changed his mind about the merits of an Oireachtas banking inquiry.

In the past, Dr Donovan had said there was no point to a banking inquiry.

But speaking on RTÉ's Morning Ireland, he said he now believes there is a need for the public to see and hear from those involved in order to make the issues more accessible.

"I don't think there will be any smoking guns or conspiracies uncovered. But people are suspicious and they need to hear from those involved," he said.

Although maintaining that no major substantive information will come from an inquiry, Dr Donovan said the inquiry is a possibility for people who were responsible for major mistakes to explain why they did what they did.

He said he believed a "small number" of informed people should conduct the inquiry, but the exact details was a political decision.

Dr Donovan said the inquiry would centre on complicated issues that could not be addressed with short five-minute speeches.

Earlier this month, the Government approved plans for an Oireachtas banking inquiry. The inquiry will look at the bank guarantee and events leading up to it, the role of banks and auditors, and the role of State institutions.

Taoiseach Enda Kenny said the Government will ensure that the probe is well-resourced and has the full co-operation of State institutions. He said it would also have regard for impending criminal trials.

Elsewhere, the author of a key report into Ireland's banking collapse expressed doubts as to whether an Oireachtas banking inquiry would bring any new information into the public domain.

Peter Nyberg, who produced his Government-commissioned report in 2011, also said a repeat of the European financial crisis is a very real risk.

"I would be pretty surprised if the parliamentary inquiry would uncover something new," Mr Nyberg said over the weekend.

The former Finnish finance ministry director-general believed that the reason those interviewed for his 2011 report were prepared to co-operate fully was the condition of anonymity they were offered.