An Irish member of parliament has said that his source is "100% certain" a politician was to benefit financially from the Nama loan sale.
But the independent TD Mick Wallace did not name anyone during questions to Irish Prime Minister Enda Kenny.
Mr Wallace alleged that Nama knew there was £7m in an Isle of Man bank account last January, but did not tell anyone.
Mr Kenny told Mr Wallace he should inform police and the Public Accounts Committee of the Irish parliament.
Speaking under parliamentary privilege, Mr Wallace asked: "Did they tell the minister of finance or did they bury it?
"You don't seem interested in getting to the truth," he told Mr Kenny.
In response to the claim by Mr Wallace that Nama was aware of a payment made to an Isle of Man account in January of this year, a Nama spokesman said that this was categorically false and incorrect.
Nama said it has already confirmed that the first it knew of this payment which, it is alleged, was connected to individuals in Northern Ireland, was two weeks ago following news reports on the issue.