Fraud squad detectives were last night granted an extension to question the former chief of Anglo Irish Bank about alleged financial irregularities.
Sean FitzPatrick — formerly chairman and chief executive of the bank — was arrested during a raid at his home in Greystones, Co Wicklow, south of Dublin.
Financial records were among documents removed as part of an investigation into the near collapse of the property lender.
The 61-year-old stepped down in December 2008 when it emerged he had hidden loans worth €87m (£78m)..
The bank's headquarters in Dublin was raided by the Garda fraud squad and investigators from the Office of the Director of Corporate Enforcement last February, but Mr FitzPatrick is the first person to be arrested.
Detectives were granted an extra 12 hours to hold him after an initial 12-hour period elapsed.
In a brief statement, Finance Minister Brian Lenihan said: “I have always stated that there is an extensive garda investigation under way. I have been cautious not to prejudice that investigation and am eager to see justice take its course.”
Earlier this month Anglo Irish Bank began legal action against Mr FitzPatrick to try to recover loans of €70m.
Former finance minister Alan Dukes, incoming head of state-run Anglo Irish Bank, has said the court case would be treated in the same way as any other debt.
Over a period of eight years up to 2007, Mr FitzPatrick temporarily transferred loans with Anglo Irish Bank to another bank before the annual report was audited.
It emerged that the loans reached €129m in 2007.
The Office of the Director of Corporate Enforcement and the Financial Regulator are also investigating whether Anglo Irish used more than €7bn of short-term deposits from Irish Life & Permanent to mask big customer deposit withdrawals.