Ireland's Central Bank snubbed warnings from a top figure in the country's leading economic think-tank eight years ago about the dangerous scale of loans to speculators and developers, an inquiry has heard.
Around two years before the country's spectacular crash, Professor John FitzGerald of the Economic and Social Research Institute (ESRI), said he became aware of "a lot of Irish investors" looking to buy up property in Poland.
The economist had been tipped off by the then Irish ambassador to Warsaw about the spending spree during a trip there in 2006 and contacted the financial regulator on his return home, he told the Oireachtas (parliament) Banking Inquiry.
"My concern was that [speculators] would have borrowed large sums of money from Irish banks, gone to Poland, then using that as equity leveraged that again," he said.
"My concern was that one Irish bank in particular had a major bank in Poland and that Ireland could be exposed unduly through this form of investment.
"So I wrote to the regulator about that."
Allied Irish Bank, which has since been taken over by the State, sold its 70% share in Poland's Bank Zachodni in 2010.
Under cross-examination from TDs and senators, Mr FitzGerald said he again contacted the Central Bank the following year over his worries about the vigour of stress tests on Irish banks.
The professor, who had responsibility for influential economic forecasts from the part publicly-funded institute, was working with banks in spring 2007 on tests designed to assess their ability to withstand financial shocks.
"I was concerned that the stress tests being undertaken by the Central Bank were not onerous enough; that they were looking at falling house prices but not taking account of the fact that a lot other things would happen at the same time," he told the hearing.
"They were not using a model to do this so I contacted the Central Bank about my concerns in that regard in 2007."
Asked if he got a satisfactory reply from the regulator on both occasions, Prof FitzGerald responded: "No"
At the time Patrick Neary was the chief executive of Dublin's Financial Regulator.
He retired in January 2009 after a damning report into his handling of secret loans to directors at former rogue lender Anglo Irish Bank.
The banking inquiry, which is investigating the events which led up to Ireland's banking crash, is expected to publish its findings later this year.