A County Down property developer is being pursued by Anglo Irish Bank for personal debts of almost £90m, the BBC has learned.
The bank claims Sam Thompson, who owns Thompson Developments and related firms, signed guarantees in 2009 making him liable for the companies' debts.
The firms have been in trouble for some time and Anglo and Ulster Bank have appointed receivers to various assets.
Mr Thompson can challenge Anglo's claims in the courts.
Personal guarantees were a feature of the Irish property boom.
Some banks, particularly Anglo, expected borrowers to put their personal assets on the line when money was being lent to their business.
In most countries, borrowers are not expected to give such guarantees - banks will simply reflect the level of perceived risk in the interest rate they charge to the business.
Some Irish business people have been ordered to honour colossal guarantees.
In January, Ulster Bank placed one of Mr Thompson's firms, Thompson Lennox, into receivership.
Thompson Lennox's last set of accounts, up to the end of April 2009, showed a £1.8m annual loss and total retained losses of around £4.5m. The company had total bank debts of more than £24m.
Thompson Developments last set of accounts, covering the year up to the end of April 2008, recorded a loss of over £1.7m, giving it a net deficit of £7.7m. It had outstanding bank loans of over £78m.
Another related company, TB Homes, in its last accounts, showed an annual loss of £187,000, total retained losses of £533,000 and bank debt of £4.6m.
Ballybreeze Estates, which has accounts up to the end of April 2009, showed an annual loss of £690,000, a net deficit of £1.8m and bank debt of £10m.
Redcliff Properties, which also has accounts up to the end of April 2009, made an annual loss of £57,000, has a net deficit of £107,000 and bank debt of £798,000.
Variety of sites
Together the companies, which are all based at Drumnabreeze House in Magheralin, have total bank debt of around £117m. No-one was at the offices when the BBC called on Friday.
They owned a variety of sites and developments around Northern Ireland in towns and cities including Armagh, Dungannon, Hillsborough, Banbridge, Dromore and Newtownbutler.
Thompson Developments speciality was building large, one-off country houses which were priced at around £1m.
Legal documents seen by the BBC show that Anglo claims the guarantees were signed in June and October.
Their case is that on June 3 2009, Mr Thompson guaranteed just over £2.5m in relation to TB Homes.
The next day he guaranteed £10m for Ballybreeze Estates.
On 22 October, he signed the biggest guarantee - £74m in relation to Thompson Developments.
On the same day he also guaranteed an £845,000 loan to Redcliff properties.
Having been served with Anglo's demand Mr Thompson can either assent to it or begin a process of challenge.