David Drumm has been arrested on an extradition warrant in the United States.
The former head of Anglo Irish Bank, who authorities in Ireland want to quiz over the collapse of the bank, was detained by US Marshals in Massachusetts.
Drumm, 48, is being held in custody ahead of an extradition hearing on Tuesday.
Ireland has long sought the extradition of Mr Drumm after he failed to be declared bankrupt in the US.
He moved to Massachusetts in 2009, six months after resigning as chief executive of the now defunct bank.
Along with two others, he stood down after hundreds of millions in directors’ loans were uncovered.
He refused to return to Ireland to be questioned about the events leading to the collapse of the bank, which was later nationalised before being wound up.
Mr Drumm fought a four-year legal battle in Boston to write off his own debts of €10.5m, But a US bankruptcy court rejected his claims in January, ruling the ex-banker was “not remotely credible”.
During the proceedings, the Irish Bank Resolution Corporation – formerly Anglo Irish Bank – fought his claims for bankruptcy, as he owed it €9m.
The Director of Public Prosecutions also recommended a number of charges be brought against Mr Drumm after a years-long probe into Anglo Irish Bank by the Garda Bureau of Fraud Investigation and the Director of Corporate Enforcement.
A spokeswoman for the the US attorney for the District of Massachusetts, Christina DiIorio-Sterling, said: “I can confirm that Mr Drumm was arrested by US Marshals in Massachusetts on an extradition warrant.
“He will remain in custody until his hearing in federal court in Boston on Tuesday.”