The National Asset Management Agency has written to the Oireachtas banking inquiry contradicting claims made by developer Johnny Ronan.

The agency said it had provided a “detailed and comprehensive rebuttal” to allegations made by Mr Ronan in his written statement to the inquiry.

Nama chief executive Brendan McDonagh said he would be keen for the inquiry to publish the document and put the facts on the public record.

Mr McDonagh said he is prevented from discussing the details of Mr Ronan’s evidence but insisted the agency deals with all debtors fairly.

“There is no question of any bias in favour of, or against, particular debtors,” he said.

“Nama deals with its debtors, regardless of their public profile or the particulars of any case, in a consistent and reasonable manner having regard to its statutory mandate.

“Any suggestion that Nama had some kind of unwritten agenda to damage debtors is utterly without foundation.”

Mr Ronan had alleged in his statement to the banking inquiry that Nama was not working in the interests of the taxpayer.

He claimed the agency had destroyed his business, Treasury Holdings, and had made a decision to take it down "whatever the consequence and regardless of the cost to the taxpayer".

Treasury Holdings has just exited Nama after repaying €300 million in debts.

Mr McDonagh said he would rather hear debtors complain about the tough approach Nama had taken than be accused of being a pushover for debtors.

“It should be clear to everyone at this stage that Nama debtors do not consider Nama to be a cosy bailout,” he said.

“We make no apology for being rigorous, professional and fair.”

Mr McDonagh said the agency was working with 70 per cent of its debtors and that not all engagements were amicable events.

However, said Mr McDonagh, there is an inherent tension and robustness between the two when Nama seeks to benefit the taxpayer and the debtor wants to benefit their own position.

Mr McDonagh also denied Nama does not have the expertise or experience it requires to complete its work.

Mr Ronan said Nama was widely referred to as the largest property company in the world but “it was led by former civil servants with no proper real- estate experience”.

“That is akin to asking an accountant to fly an airplane or a butcher to perform heart surgery,” he said.