Central Bank governor Patrick Honohan never referred to plans for new rules on mortgage deposits in a pre-Budget letter to the finance minister - even though the measures were announced just a fortnight later.
In a lengthy letter to Michael Noonan late last September, Professor Honohan said officials in Dame Street were keeping the housing market under close review, especially around credit conditions.
And he noted the need for measures to deal with the shortage of supply in Dublin.
But he made no reference to the plans being drawn up which would require home buyers to have a hefty deposit, and which were announced just weeks later.
"The Central Bank continues to keep the housing market situation under close review, especially with regard to the potential influence of credit conditions," the Governor wrote.
"The strong increase in housing prices in the Dublin region mainly reflects supply shortages calling, as you recognise, for a range of supply-side measures."
Prof Honohan cautioned that any policy initiatives that aimed at increasing demand were "likely to put further upward pressure on prices".
"In this context, the ending of the capital gains tax relief scheme scheduled for this year will be a step in the right direction," Prof Honohan said.
The letter to the Minister, released under Freedom of Information to the Irish Independent, was dated September 22. The Central Bank published its so-called macro-prudential measures for mortgage lending on October 7.
The rules - subsequently amended following a public consultation process - stipulate borrowings by first-time buyers up to €220,000 will be approved with a deposit of as little as 10pc.
But any amount over €220,000 will require a 20pc deposit for that portion of the mortgage. Non-first-time buyers will have to come up with a 20pc deposit.
Mr Honohan has said that the decision to give first-time buyers some relief was to ensure that those looking to get on the property ladder should not be unfairly punished.
He said first-time buyers were not responsible for the previous housing bubble.