BRIAN O'Donnell and his wife Dr Mary Pat O'Donnell owe Bank of Ireland €75m.
The massive debts helped finance a global property empire. The couple lived in one of the most luxurious family homes in Ireland.
Now, they could emerge debt-free in just a year if their UK bankruptcy goes ahead. They are just the latest in a growing number of Irish debtors seeking to be declared bankrupt abroad.
Yesterday, the High Court in Dublin was told that the couple had applied for bankruptcy in the UK. The shock news came during an application by Bank of Ireland to cross-examine the couple about ownership of their vast former property empire.
The O'Donnells and the bank have been involved in ongoing legal action for more than a year over the debts.
Yesterday, Bank of Ireland said it was concerned by what it said were "alarming" discrepancies between statements setting out what assets the couple own that were made in March 2011 and February of this year.
The bank claimed that the statements directly contradicted each other, in that properties the couple previously claimed to own were now listed as owned or part-owned by their children.
The properties of which the bank is seeking possession include the O'Donnell family home, one of the most luxurious properties in Dublin.
The house was valued at €30m during the boom. Even today, it is said to be worth between €6m and €7m.
Bank of Ireland's Des Hanrahan said the bank was concerned because the most recent statement said the home was owned by an Isle of Man company, Vico Ltd, which is owned by the couple's four children.
Judge Kelly granted the application. He ordered the O'Donnells to attend court next month in Dublin, despite their UK move.
It was only during the hearing that lawyers for the O'Donnells revealed that the couple were not in Dublin and that they had already applied for and been granted bankruptcy in the UK. However, Bank of Ireland is understood to be exploring options to try to block that move.
Sources at the bank told the Irish Independent that the O'Donnells had applied for bankruptcy but had not yet been formally declared bankrupt.
Insiders claim it means that the bank still has a window when it can attempt to prevent the bankruptcy application.
If the bank does try to block the O'Donnells' move, it will need to make its case in front of a UK judge at a bankruptcy hearing around two months from now.
Yesterday, at the High Court, Mr Justice Peter Kelly had harsh words for Brian O'Donnell in particular. The judge said he was "not impressed" by a radio interview given by Mr O'Donnell last year, when he had complained about the bank but then opted not to appear in court himself.
The judge's words are especially telling because Mr O'Donnell was for many years one of Ireland's top lawyers as managing partner at top law firm William Fry.
Efforts to block a UK bankruptcy are likely to focus on whether the couple are resident in the UK.
Sources in London said Mr and Mrs O'Donnell were now living there. The bank is said to be disputing that claim.
This newspaper has also learned that the O'Donnells offered to make a voluntary settlement with the bank a month ago, but their offer was refused in writing.