Officials at Anglo Irish Bank described a meeting with the Financial Regulator in January 2009 as "an ambush", David Drumm's conspiracy to defraud trial has heard.
Kevin Kelly, who was a finance manager at Anglo, said the meeting he attended with Con Horan and other officials from the regulator was "tense and very robust".
"In essence the Financial Regulator was querying Anglo's treatment of the Irish Life transactions," he told a Dublin Circuit Criminal Court jury on day 47 of the trial.
Mr Drumm, the bank's former CEO, accepts that multi-million euro transactions took place between Anglo and Irish Life & Permanent in 2008, but disputes that they were fraudulent or dishonest.
Mr Kelly told Bernard Condon SC, defending, that he and Matt Moran, former CFO at Anglo, attended the meeting on 14 January 2009 and said Patrick Neary, the financial regulator, was not present.
Mr Condon asked the witness if he agreed with Mr Moran's description of the meeting as "an ambush".
"That was certainly the tone," Mr Kelly said.
He said Anglo's audit committee had met and discussed the accounting used in the ILP transactions days previously.
Mr Kelly said this information was provided to regulator officials during the January meeting.
He also said that regulator staff requested a meeting with Anglo's auditors, Ernst & Young.
Following his cross-examination, Mr Kelly was asked by Paul O'Higgins SC, prosecuting, about a note, added by Anglo directors in February 2009, to the bank's final set of 2008 accounts.
"Would a person be able to detect the ILP transactions in Anglo's accounts without this note?" Mr O'Higgins asked.
"I don't believe so, no," Mr Kelly replied.
Mr Drumm of Skerries, Co Dublin, has pleaded not guilty to conspiring with former bank officials Denis Casey, William McAteer, John Bowe and others to defraud depositors and investors at Anglo by "dishonestly" creating the impression that deposits were €7.2 billion larger than they were in 2008.
The former Anglo CEO has also pleaded not guilty to false accounting on 3 December 2008, by furnishing information to the market that Anglo's 2008 deposits were €7.2bn larger than they were.
The trial is now in its ninth week, and continues before Judge Karen O'Connor and a jury.